Question bank.

353 questions · ● reported with a source · ○ likely, from their products

• Design a URL ShortenerSystem design · reported at 16
  ● Amazon● Apple● Freshworks● Intuit● JioHotstar● MakeMyTrip● Microsoft● Morgan Stanley● Nykaa● Oracle● Postman● Salesforce● ShareChat● Sprinklr● Urban Company● Walmart Global TechIP-01 · Design a URL Shortener →W01 · BOSS · Design a URL Shortener at Scale →IP-04 · Design a Unique ID Generator →
• Design a Parking LotLow-level design · reported at 13
  ● Amazon● Freshworks● Goldman Sachs● MakeMyTrip● Microsoft● Morgan Stanley● Nykaa● PayPal● Razorpay● Salesforce● Swiggy● Uber● ZohoLLD-01 · Design a Parking Lot →
• Design a Rate LimiterSystem design · reported at 9
  ● Freshworks● Google○ Juspay● LinkedIn● Microsoft● Nykaa● Ola● Oracle● Paytm○ Stripe○ Zerodha● ZomatoIP-02 · Design a Rate Limiter →W01 · DAY 03 · Rate Limiting at Scale →W09 · DAY 05 · Security Architecture →
• Design a News FeedSystem design · reported at 9
  ● Goldman Sachs○ LinkedIn● Meta● Microsoft● PhonePe● Postman● ShareChat● Stripe● Swiggy● Walmart Global TechIP-07 · Design a News Feed →SQ-10 · Twitter/X →W04 · DAY 04 · Feed Caching →
• Design a Distributed Job SchedulerSystem design · reported at 9
  ● Amazon● Atlassian● LinkedIn● Microsoft● Netflix● PhonePe● Postman● Razorpay● SwiggyIP-17 · Design a Distributed Job Scheduler →W02 · DAY 05 · Distributed Cron & Job Scheduling →W05 · DAY 05 · Leader Election and Coordination →
• Design SplitwiseLow-level design · reported at 9
  ● Amazon● Groww● MakeMyTrip● Meesho● Nykaa● PhonePe● Razorpay● ShareChat● SwiggyLLD-06 · Design a Bill-Splitting App (Splitwise) →
• Design a Notification SystemSystem design · reported at 8
  ● Amazon○ Apple○ Atlassian○ CRED● Goldman Sachs● Groww○ Intuit○ LinkedIn○ Meesho● Myntra○ Netflix● Ola● Oracle● Razorpay● ZomatoIP-06 · Design a Notification System →W06 · DAY 01 · Designing a Real-Time Notification Platform →W06 · DAY 02 · The Delivery Pipeline: Guarantees, Priorities and Preferences →
• Design a File Sync ServiceSystem design · reported at 6
  ○ Adobe● Amazon○ Apple● CRED○ Google● JPMorgan Chase● Microsoft● Nykaa● OracleIP-10 · Design a File Sync Service (Dropbox / Google Drive) →SQ-08 · AWS S3 →W05 · DAY 04 · Conflict Resolution →
• Design an Elevator SystemLow-level design · reported at 6
  ● Adobe● Apple● MakeMyTrip● Microsoft● PayPal● SprinklrLLD-04 · Design an Elevator System →
• Design a Payment SystemSystem design · reported at 5
  ● Goldman Sachs○ Intuit○ JPMorgan Chase○ Juspay● Microsoft● Myntra● PayPal○ Paytm○ PhonePe○ Razorpay● ShareChat○ Stripe○ UberIP-20 · Design a Payment System →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →W05 · DAY 01 · Consistency Models →
• Design a Chat SystemSystem design · reported at 5
  ● Amazon● Freshworks● JioHotstar● Meta○ Microsoft○ ShareChat● UberIP-08 · Design a Chat System →SQ-02 · WhatsApp Messaging →
• Design a Ride-Hailing ServiceSystem design · reported at 5
  ● Amazon● CRED● Freshworks● MakeMyTrip○ Ola○ Rapido● UberSQ-09 · Uber →IP-13 · Design a Proximity Service →W01 · DAY 04 · Hot Keys and Skew →
• Design a Web CrawlerSystem design · reported at 5
  ● Atlassian● Freshworks● InMobi● Meta● MicrosoftIP-05 · Design a Web Crawler →W02 · DAY 05 · Distributed Cron & Job Scheduling →W03 · DAY 01 · Queue vs Stream →
• Design an In-Memory Message QueueLow-level design · reported at 5
  ● Adobe● Intuit● Microsoft● Salesforce● UberLLD-08 · Design a Logging Framework (Pub-Sub) →IP-18 · Design a Distributed Message Queue →
• Design an LRU CacheLow-level design · reported at 5
  ● MakeMyTrip● Microsoft● Paytm● Rapido● SprinklrLLD-02 · Design an LRU Cache →IP-11 · Design a Distributed Cache →
• Design Snake and LadderLow-level design · reported at 5
  ● Goldman Sachs● Meesho● Salesforce● Swiggy● Walmart Global Tech
• Design a Real-Time LeaderboardSystem design · reported at 4
  ● Apple● Dream11● Groww● MakeMyTrip○ MetaIP-14 · Design a Real-Time Leaderboard →W01 · DAY 04 · Hot Keys and Skew →
• Design a Ticket Booking SystemSystem design · reported at 4
  ● Flipkart● Morgan Stanley● Paytm● Zoho○ ZomatoSQ-16 · BookMyShow Seat Booking →LLD-05 · Design a Movie Ticket Booking System →SQ-11 · IRCTC Tatkal Ticket Booking System →
• Design a Chess GameLow-level design · reported at 4
  ● Adobe● Apple● Sprinklr● Urban Company
• Design a Logging SystemSystem design · reported at 4
  ● Apple● Freshworks● Google● Walmart Global TechW08 · DAY 01 · Event Ingestion at Scale →W08 · DAY 05 · Query Layer and Optimization →W10 · DAY 02 · Observability →
• Design a Rate Limiter (LLD)Low-level design · reported at 4
  ● Atlassian● PayPal● Postman● RazorpayLLD-03 · Design a Rate Limiter →IP-02 · Design a Rate Limiter →W01 · DAY 03 · Rate Limiting at Scale →
• Design a Vending MachineLow-level design · reported at 4
  ● Amazon● Goldman Sachs● Meesho● Urban CompanyLLD-07 · Design a Vending Machine →
• Design an In-Memory File SystemLow-level design · reported at 4
  ● PayPal● Salesforce● Sprinklr● Zoho
• Design a Food Delivery SystemSystem design · reported at 3
  ● Freshworks● JioHotstar● Ola○ Swiggy○ Uber○ ZomatoSQ-17 · Swiggy Food Delivery →W06 · BOSS · Food Delivery Order System →W03 · BOSS · Event-Driven Food Delivery Order System →
• Design a Video Streaming ServiceSystem design · reported at 3
  ○ Google● Meta○ Netflix● Ola● Oracle○ ShareChatSQ-19 · YouTube Video Platform →SQ-06 · Netflix Streaming →W04 · DAY 05 · Multi-Tier Caching →
• Design a Metrics Monitoring and Alerting SystemSystem design · reported at 3
  ● Dream11● LinkedIn○ Netflix● StripeIP-15 · Design a Metrics Monitoring and Alerting System →W10 · DAY 02 · Observability →W08 · DAY 03 · Data Modeling for Analytics →
• Design a cab booking systemLow-level design · reported at 3
  ● Meesho● Razorpay● SwiggySQ-09 · Uber →IP-13 · Design a Proximity Service →
• Design a Car Rental SystemLow-level design · reported at 3
  ● Adobe● Flipkart● Walmart Global TechLLD-05 · Design a Movie Ticket Booking System →IP-19 · Design a Hotel Reservation System →LLD-01 · Design a Parking Lot →
• Design a Logging FrameworkLow-level design · reported at 3
  ● Morgan Stanley● Razorpay● UberLLD-08 · Design a Logging Framework (Pub-Sub) →
• Design a Movie Ticket Booking System (LLD)Low-level design · reported at 3
  ● JioHotstar● PayPal● Urban CompanyLLD-05 · Design a Movie Ticket Booking System →SQ-16 · BookMyShow Seat Booking →
• Design a Collaborative EditorSystem design · reported at 2
  ○ Adobe○ Atlassian○ Google○ Microsoft● Postman● RazorpaySQ-15 · Figma Multiplayer Editing →SQ-20 · Google Docs Collaboration →W05 · DAY 04 · Conflict Resolution →
• Design a Proximity ServiceSystem design · reported at 2
  ○ Google● Meta○ Ola○ Rapido● Uber○ ZomatoIP-13 · Design a Proximity Service →W01 · DAY 01 · Partitioning Deep-Dive →W01 · DAY 04 · Hot Keys and Skew →
• Design a Stock Exchange / Trading PlatformSystem design · reported at 2
  ● Dream11● InMobi○ Morgan Stanley○ ZerodhaSQ-13 · Zerodha Kite Trading Platform →W05 · DAY 05 · Leader Election and Coordination →W05 · DAY 01 · Consistency Models →
• Design Webhook DeliverySystem design · reported at 2
  ○ Atlassian● Stripe● UberW02 · DAY 04 · Webhook Delivery System →W03 · DAY 04 · Dead Letters and Poison Pills →W02 · DAY 02 · Idempotency in Practice →
• Design a Circuit Breaker (LLD)Low-level design · reported at 2
  ● PayPal● ShareChatW02 · DAY 03 · Circuit Breakers →
• Design a Distributed Message QueueSystem design · reported at 2
  ● Apple● LinkedInIP-18 · Design a Distributed Message Queue →W03 · DAY 01 · Queue vs Stream →W02 · DAY 02 · Idempotency in Practice →
• Design a Doctor Appointment Booking SystemLow-level design · reported at 2
  ● Intuit● SalesforceLLD-05 · Design a Movie Ticket Booking System →IP-19 · Design a Hotel Reservation System →
• Design a Leaderboard (LLD)Low-level design · reported at 2
  ● Intuit● UberIP-14 · Design a Real-Time Leaderboard →
• Design a Library Management SystemLow-level design · reported at 2
  ● Walmart Global Tech● Zoho
• Design a Ludo gameLow-level design · reported at 2
  ● ShareChat● Urban Company
• Design a News Summary App (Inshorts)System design · reported at 2
  ● Goldman Sachs● GoogleIP-07 · Design a News Feed →W04 · DAY 04 · Feed Caching →IP-05 · Design a Web Crawler →
• Design a Snake GameLow-level design · reported at 2
  ● Atlassian● Zomato
• Design a Stock Exchange / Trading PlatformLow-level design · reported at 2
  ● Goldman Sachs● JioHotstarSQ-13 · Zerodha Kite Trading Platform →
• Design a stock exchange order bookLow-level design · reported at 2
  ● Groww● MeeshoSQ-13 · Zerodha Kite Trading Platform →
• Design a Tagging SystemSystem design · reported at 2
  ● Atlassian● SalesforceW09 · DAY 01 · Tenant Isolation Strategies →W07 · DAY 02 · Indexing Pipeline →W01 · DAY 04 · Hot Keys and Skew →
• Design an Image Hosting ServiceSystem design · reported at 2
  ● Google● IntuitSQ-08 · AWS S3 →W04 · DAY 05 · Multi-Tier Caching →SQ-21 · Instagram Feed and Stories →
• Design an IoT Sensor Data PlatformSystem design · reported at 2
  ● Amazon● AppleW08 · DAY 01 · Event Ingestion at Scale →IP-15 · Design a Metrics Monitoring and Alerting System →W03 · DAY 03 · Backpressure and Flow Control →
• Design an Order Management SystemSystem design · reported at 2
  ● Goldman Sachs● Walmart Global TechW03 · BOSS · Event-Driven Food Delivery Order System →W05 · DAY 03 · Saga Orchestration Deep Dive →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →
• Design InstagramSystem design · reported at 2
  ● Oracle● PhonePeSQ-21 · Instagram Feed and Stories →IP-07 · Design a News Feed →
• Design Instagram StoriesSystem design · reported at 2
  ● Goldman Sachs● MetaSQ-21 · Instagram Feed and Stories →W04 · DAY 05 · Multi-Tier Caching →
• Design TwitterSystem design · reported at 2
  ● InMobi● SprinklrSQ-10 · Twitter/X →IP-07 · Design a News Feed →
• Design a Digital WalletSystem design · reported at 1
  ● Dream11○ PayPal○ Paytm○ StripeIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →SQ-01 · India's UPI →
• Design Typeahead Search (Autocomplete)System design · reported at 1
  ○ Google○ LinkedIn● Microsoft○ MyntraIP-09 · Design Typeahead Search (Autocomplete) →W07 · DAY 04 · Typeahead at Scale: Autocomplete, Spelling and Facets →
• Design a Cab Booking App (LLD)Low-level design · reported at 1
  ○ Rapido● Urban CompanySQ-09 · Uber →
• Design a Distributed CacheSystem design · reported at 1
  ● Google○ NetflixIP-11 · Design a Distributed Cache →W04 · DAY 01 · Caching Patterns →W01 · DAY 04 · Hot Keys and Skew →
• Break a Monolithic Shopping App into MicroservicesSystem design · reported at 1
  ● JPMorgan ChaseW03 · BOSS · Event-Driven Food Delivery Order System →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →W03 · DAY 02 · Transactional Outbox →
• Build a Friends Online-Status Service (Machine Coding)Low-level design · reported at 1
  ● PostmanIP-08 · Design a Chat System →W01 · DAY 05 · Session Store Design →
• Build a Real-Time Log Watcher like tail -f (Machine Coding)Low-level design · reported at 1
  ● BrowserStackW03 · DAY 03 · Backpressure and Flow Control →W00 · PART 4 · Networking Fundamentals for System Design →W00 · PART 5 · Operating System Concepts for System Design →
• Build a Simple Key-Value Store like pickleDBLow-level design · reported at 1
  ● PostmanIP-03 · Design a Distributed Key-Value Store →
• Build a Web Service that Controls Browsers (Machine Coding)Low-level design · reported at 1
  ● BrowserStackW00 · PART 5 · Operating System Concepts for System Design →
• Build an In-Memory Pub-Sub like Kafka (Machine Coding)Low-level design · reported at 1
  ● InMobiLLD-08 · Design a Logging Framework (Pub-Sub) →IP-18 · Design a Distributed Message Queue →
• Compute metrics over a time range from an event logLow-level design · reported at 1
  ● CREDIP-15 · Design a Metrics Monitoring and Alerting System →W08 · DAY 03 · Data Modeling for Analytics →
• Debug a system from its log fileConcept · reported at 1
  ● JuspayW10 · DAY 02 · Observability →W10 · DAY 05 · Incident Management →
• Design a Bingo gameLow-level design · reported at 1
  ● Paytm
• Design a Book-Shelf Service like Goodreads (REST APIs)Low-level design · reported at 1
  ● PayPalW04 · DAY 01 · Caching Patterns →
• Design a booking aggregator for movies and cabsSystem design · reported at 1
  ● GrowwSQ-16 · BookMyShow Seat Booking →W10 · DAY 02 · Observability →
• Design a Browser Automation System without SeleniumLow-level design · reported at 1
  ● BrowserStackW00 · PART 4 · Networking Fundamentals for System Design →
• Design a Buy Now Pay Later (BNPL) systemLow-level design · reported at 1
  ● FlipkartIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →
• Design a Cache with Configurable Eviction Policy (LLD)Low-level design · reported at 1
  ● PayPalLLD-02 · Design an LRU Cache →IP-11 · Design a Distributed Cache →
• Design a calendarLow-level design · reported at 1
  ● Myntra
• Design a Calendar App like Google CalendarLow-level design · reported at 1
  ● JioHotstarIP-06 · Design a Notification System →
• Design a Calendar App like Google CalendarSystem design · reported at 1
  ● PayPalIP-06 · Design a Notification System →IP-17 · Design a Distributed Job Scheduler →
• Design a Calendar Invite ServiceSystem design · reported at 1
  ● LinkedInIP-06 · Design a Notification System →IP-19 · Design a Hotel Reservation System →
• Design a Call Taxi Booking Application (LLD)Low-level design · reported at 1
  ● ZohoSQ-09 · Uber →
• Design a Carpool Ride-Sharing App (LLD)Low-level design · reported at 1
  ● Urban CompanySQ-09 · Uber →IP-13 · Design a Proximity Service →
• Design a cart and checkout systemLow-level design · reported at 1
  ● MeeshoW02 · DAY 02 · Idempotency in Practice →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →
• Design a Catalog Event Enrichment PipelineSystem design · reported at 1
  ● LinkedInW08 · DAY 01 · Event Ingestion at Scale →W08 · DAY 02 · Streaming vs Batch Processing →
• Design a chess move validatorLow-level design · reported at 1
  ● Groww
• Design a clinic appointment booking systemLow-level design · reported at 1
  ● MeeshoLLD-05 · Design a Movie Ticket Booking System →IP-19 · Design a Hotel Reservation System →
• Design a Collaborative Coding Pad (CoderPad)System design · reported at 1
  ● LinkedInSQ-20 · Google Docs Collaboration →SQ-15 · Figma Multiplayer Editing →
• Design a Collaborative Document Editor (LLD)Low-level design · reported at 1
  ● AmazonSQ-20 · Google Docs Collaboration →W05 · DAY 04 · Conflict Resolution →
• Design a Concurrent Hash MapLow-level design · reported at 1
  ● Walmart Global TechW00 · PART 5 · Operating System Concepts for System Design →W01 · DAY 01 · Partitioning Deep-Dive →
• Design a conference room booking systemLow-level design · reported at 1
  ● FlipkartLLD-05 · Design a Movie Ticket Booking System →IP-19 · Design a Hotel Reservation System →
• Design a Continue-Watching (Resume Video) FeatureSystem design · reported at 1
  ● JioHotstarSQ-06 · Netflix Streaming →W01 · DAY 05 · Session Store Design →
• Design a coupon service for an e-commerce platformSystem design · reported at 1
  ● ShareChatW04 · DAY 01 · Caching Patterns →W02 · DAY 02 · Idempotency in Practice →
• Design a coupon-based discount systemLow-level design · reported at 1
  ● SwiggyW04 · DAY 01 · Caching Patterns →
• Design a Course Registration SystemSystem design · reported at 1
  ● Goldman SachsSQ-11 · IRCTC Tatkal Ticket Booking System →W01 · DAY 04 · Hot Keys and Skew →
• Design a Customer Loyalty Points ProgramLow-level design · reported at 1
  ● AmazonW02 · DAY 02 · Idempotency in Practice →IP-20 · Design a Payment System →
• Design a Customer Support Chatbot for Hotel and Flight BookingsSystem design · reported at 1
  ● MakeMyTripW03 · BOSS · Event-Driven Food Delivery Order System →W02 · DAY 03 · Circuit Breakers →
• Design a Delayed Task SchedulerLow-level design · reported at 1
  ● LinkedInW02 · DAY 05 · Distributed Cron & Job Scheduling →W00 · PART 5 · Operating System Concepts for System Design →
• Design a delivery-partner payout system with offersLow-level design · reported at 1
  ● SwiggyIP-20 · Design a Payment System →
• Design a Distributed Key-Value StoreSystem design · reported at 1
  ● LinkedInIP-03 · Design a Distributed Key-Value Store →W01 · DAY 01 · Partitioning Deep-Dive →W01 · DAY 02 · Replication Trade-offs →
• Design a Document-Sharing ApplicationSystem design · reported at 1
  ● FreshworksIP-10 · Design a File Sync Service (Dropbox / Google Drive) →SQ-08 · AWS S3 →W09 · DAY 05 · Security Architecture →
• Design a Fantasy Sports Platform like Dream11System design · reported at 1
  ● MakeMyTripIP-14 · Design a Real-Time Leaderboard →W02 · BOSS · The Ultimate System Design Interview →W04 · DAY 03 · Thundering Herd →
• Design a Fast-Food Outlet Ordering System like McDonald's (LLD)Low-level design · reported at 1
  ● Nykaa
• Design a feature of a video-call app like Google MeetSystem design · reported at 1
  ● Myntra
• Design a File Management System (LLD)Low-level design · reported at 1
  ● FreshworksW00 · PART 5 · Operating System Concepts for System Design →
• Design a fitness-centre slot booking app like CultLow-level design · reported at 1
  ● MeeshoLLD-05 · Design a Movie Ticket Booking System →
• Design a flight booking system like MakeMyTripSystem design · reported at 1
  ● CREDIP-19 · Design a Hotel Reservation System →SQ-11 · IRCTC Tatkal Ticket Booking System →
• Design a Food Delivery App (LLD)Low-level design · reported at 1
  ● Morgan StanleySQ-17 · Swiggy Food Delivery →W03 · BOSS · Event-Driven Food Delivery Order System →
• Design a hackathon platform with scoring and recommendationsLow-level design · reported at 1
  ● PhonePeIP-14 · Design a Real-Time Leaderboard →
• Design a home-services marketplace like UrbanClapSystem design · reported at 1
  ● FlipkartIP-13 · Design a Proximity Service →SQ-09 · Uber →
• Design a Hospital Appointment System with Patient Priorities (LLD)Low-level design · reported at 1
  ● InMobi
• Design a Jira-like task management toolLow-level design · reported at 1
  ● Flipkart
• Design a Key-Value Store with TransactionsLow-level design · reported at 1
  ● UberIP-03 · Design a Distributed Key-Value Store →W05 · DAY 01 · Consistency Models →
• Design a Keyword Search FeatureSystem design · reported at 1
  ● MetaW07 · DAY 01 · Search Fundamentals & Architecture →W07 · DAY 02 · Indexing Pipeline →
• Design a ledger to store transactions from many servicesSystem design · reported at 1
  ● FlipkartIP-20 · Design a Payment System →W03 · DAY 05 · Audit Log System →W02 · DAY 02 · Idempotency in Practice →
• Design a live cricket score app like Cricbuzz (LLD)Low-level design · reported at 1
  ● ShareChatW04 · DAY 04 · Feed Caching →
• Design a Live Cricket Score App like Cricbuzz (Schema)Low-level design · reported at 1
  ● OracleW04 · DAY 03 · Thundering Herd →W08 · DAY 03 · Data Modeling for Analytics →
• Design a Live Cricket Score ClientSystem design · reported at 1
  ● AdobeW02 · DAY 01 · Timeout Hell →W04 · DAY 01 · Caching Patterns →W03 · DAY 03 · Backpressure and Flow Control →
• Design a load balancerLow-level design · reported at 1
  ● RazorpayW00 · PART 2 · Infrastructure Building Blocks →W02 · DAY 03 · Circuit Breakers →
• Design a Load BalancerSystem design · reported at 1
  ● MetaW00 · PART 2 · Infrastructure Building Blocks →W00 · PART 4 · Networking Fundamentals for System Design →
• Design a Log Scanner that Raises Tickets on ExceptionsSystem design · reported at 1
  ● OracleW10 · DAY 02 · Observability →W08 · DAY 01 · Event Ingestion at Scale →
• Design a Logger Rate LimiterLow-level design · reported at 1
  ● GoogleLLD-03 · Design a Rate Limiter →LLD-08 · Design a Logging Framework (Pub-Sub) →
• Design a malicious URL detection serviceSystem design · reported at 1
  ● PhonePeIP-11 · Design a Distributed Cache →W04 · DAY 01 · Caching Patterns →
• Design a Meeting Slot RecommenderLow-level design · reported at 1
  ● Salesforce
• Design a Memory Management SystemLow-level design · reported at 1
  ● AdobeW00 · PART 5 · Operating System Concepts for System Design →
• Design a message brokerLow-level design · reported at 1
  ● Dream11IP-18 · Design a Distributed Message Queue →LLD-08 · Design a Logging Framework (Pub-Sub) →
• Design a microprocessor with registersLow-level design · reported at 1
  ● CRED
• Design a Multithreaded Job SchedulerLow-level design · reported at 1
  ● UberIP-17 · Design a Distributed Job Scheduler →W02 · DAY 05 · Distributed Cron & Job Scheduling →
• Design a music streaming service like SpotifySystem design · reported at 1
  ● FlipkartSQ-07 · Spotify →W07 · DAY 01 · Search Fundamentals & Architecture →
• Design a Nested Comments System (Machine Coding)Low-level design · reported at 1
  ● Postman
• Design a News AppSystem design · reported at 1
  ● AppleIP-07 · Design a News Feed →W04 · DAY 04 · Feed Caching →W04 · DAY 05 · Multi-Tier Caching →
• Design a Notification SystemLow-level design · reported at 1
  ● AdobeIP-06 · Design a Notification System →W06 · DAY 02 · The Delivery Pipeline: Guarantees, Priorities and Preferences →
• Design a Package Tracking SystemLow-level design · reported at 1
  ● Walmart Global TechW03 · DAY 05 · Audit Log System →IP-06 · Design a Notification System →
• Design a Page Visit CounterSystem design · reported at 1
  ● IntuitW01 · DAY 04 · Hot Keys and Skew →IP-16 · Design an Ad Click Aggregation System →
• Design a paginated transaction-history APISystem design · reported at 1
  ● ZomatoW08 · DAY 05 · Query Layer and Optimization →W01 · DAY 01 · Partitioning Deep-Dive →
• Design a Parking Finder that Shows Free Spaces NearbySystem design · reported at 1
  ● OracleIP-13 · Design a Proximity Service →LLD-01 · Design a Parking Lot →
• Design a Parking Lot System that Uses an AI Number-Plate CameraSystem design · reported at 1
  ● JPMorgan ChaseLLD-01 · Design a Parking Lot →W02 · DAY 01 · Timeout Hell →W03 · DAY 01 · Queue vs Stream →
• Design a Payment Aggregator that Routes for the Best Success RateLow-level design · reported at 1
  ● Urban CompanySQ-18 · Razorpay Payment Gateway →IP-20 · Design a Payment System →W02 · DAY 03 · Circuit Breakers →
• Design a Payment GatewaySystem design · reported at 1
  ● PayPalSQ-18 · Razorpay Payment Gateway →IP-20 · Design a Payment System →W02 · DAY 04 · Webhook Delivery System →
• Design a payment gateway (machine coding)Low-level design · reported at 1
  ● PhonePeSQ-18 · Razorpay Payment Gateway →IP-20 · Design a Payment System →
• Design a payment-method recommendation systemLow-level design · reported at 1
  ● CREDIP-20 · Design a Payment System →SQ-18 · Razorpay Payment Gateway →
• Design a payments risk management serviceSystem design · reported at 1
  ● PaytmW08 · DAY 02 · Streaming vs Batch Processing →W02 · DAY 01 · Timeout Hell →
• Design a peer-to-peer chess gameSystem design · reported at 1
  ● ZomatoW05 · BOSS · Multiplayer Game Matchmaking System →
• Design a pendency system that counts in-flight entitiesLow-level design · reported at 1
  ● PhonePe
• Design a persistent pub-sub queue with ordered deliveryLow-level design · reported at 1
  ● RazorpayIP-18 · Design a Distributed Message Queue →LLD-08 · Design a Logging Framework (Pub-Sub) →
• Design a phonebook appLow-level design · reported at 1
  ● FlipkartIP-09 · Design Typeahead Search (Autocomplete) →
• Design a pipeline that moves stock candle data from cache to SQLSystem design · reported at 1
  ● GrowwW08 · DAY 02 · Streaming vs Batch Processing →W04 · DAY 01 · Caching Patterns →W08 · DAY 03 · Data Modeling for Analytics →
• Design a Point-of-Sale SystemSystem design · reported at 1
  ● AppleW02 · DAY 02 · Idempotency in Practice →W05 · DAY 04 · Conflict Resolution →
• Design a Popularity CounterLow-level design · reported at 1
  ● Walmart Global TechIP-14 · Design a Real-Time Leaderboard →
• Design a prepaid mini walletLow-level design · reported at 1
  ● PhonePeIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →
• Design a Railway Ticket Reservation System (LLD)Low-level design · reported at 1
  ● ZohoSQ-11 · IRCTC Tatkal Ticket Booking System →LLD-05 · Design a Movie Ticket Booking System →
• Design a Real-Time Trending Topics ServiceSystem design · reported at 1
  ● GoogleW08 · DAY 02 · Streaming vs Batch Processing →SQ-10 · Twitter/X →IP-16 · Design an Ad Click Aggregation System →
• Design a Recommendation SystemSystem design · reported at 1
  ● SalesforceW08 · DAY 02 · Streaming vs Batch Processing →W04 · DAY 01 · Caching Patterns →
• Design a Recommendation System for a Streaming AppSystem design · reported at 1
  ● JioHotstarSQ-06 · Netflix Streaming →W08 · DAY 02 · Streaming vs Batch Processing →
• Design a Recommendation System for an Online Book StoreSystem design · reported at 1
  ● OracleW08 · DAY 02 · Streaming vs Batch Processing →
• Design a relational database like MySQLSystem design · reported at 1
  ● FlipkartIP-03 · Design a Distributed Key-Value Store →W01 · DAY 02 · Replication Trade-offs →
• Design a Resource Inventory Service for a Cloud ProviderSystem design · reported at 1
  ● OracleW01 · DAY 01 · Partitioning Deep-Dive →W07 · DAY 01 · Search Fundamentals & Architecture →W09 · DAY 01 · Tenant Isolation Strategies →
• Design a Restaurant Discovery FeedSystem design · reported at 1
  ● UberSQ-17 · Swiggy Food Delivery →IP-13 · Design a Proximity Service →W04 · DAY 04 · Feed Caching →
• Design a Restaurant Reservation SystemLow-level design · reported at 1
  ● Goldman SachsIP-19 · Design a Hotel Reservation System →LLD-05 · Design a Movie Ticket Booking System →
• Design a Reusable Library Shared Across Many ServicesLow-level design · reported at 1
  ● JPMorgan ChaseW02 · DAY 03 · Circuit Breakers →W02 · DAY 01 · Timeout Hell →
• Design a reviews and ratings system with moderationSystem design · reported at 1
  ● MyntraW03 · DAY 01 · Queue vs Stream →W04 · DAY 01 · Caching Patterns →
• Design a Round-Robin Reverse ProxyLow-level design · reported at 1
  ● BrowserStackW00 · PART 2 · Infrastructure Building Blocks →IP-02 · Design a Rate Limiter →
• Design a Rules EngineSystem design · reported at 1
  ● SalesforceW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →W04 · DAY 02 · Invalidation Strategies →
• Design a Scalable Secrets Storage ServiceSystem design · reported at 1
  ● PayPalW09 · DAY 05 · Security Architecture →IP-03 · Design a Distributed Key-Value Store →
• Design a Secrets VaultSystem design · reported at 1
  ● AdobeW09 · DAY 05 · Security Architecture →W09 · DAY 01 · Tenant Isolation Strategies →
• Design a Server-Driven Video Feed for a Mobile AppSystem design · reported at 1
  ● RapidoSQ-19 · YouTube Video Platform →W04 · DAY 04 · Feed Caching →
• Design a service that calls an endpoint at a fixed intervalLow-level design · reported at 1
  ● CREDIP-17 · Design a Distributed Job Scheduler →W02 · DAY 05 · Distributed Cron & Job Scheduling →
• Design a Service That Indexes a Social Network's FeedSystem design · reported at 1
  ● GoogleW07 · DAY 02 · Indexing Pipeline →W07 · DAY 01 · Search Fundamentals & Architecture →SQ-10 · Twitter/X →
• Design a Social Media Site and Its DatabaseSystem design · reported at 1
  ● BrowserStackIP-07 · Design a News Feed →SQ-21 · Instagram Feed and Stories →
• Design a social network like Facebook (LLD)Low-level design · reported at 1
  ● MeeshoIP-07 · Design a News Feed →
• Design a Social Network like Instagram or FacebookSystem design · reported at 1
  ● FreshworksIP-07 · Design a News Feed →SQ-21 · Instagram Feed and Stories →W04 · DAY 04 · Feed Caching →
• Design a song recognition service like ShazamSystem design · reported at 1
  ● PhonePe
• Design a Split-and-Merge Task Processing SystemSystem design · reported at 1
  ● Goldman SachsW08 · DAY 02 · Streaming vs Batch Processing →IP-17 · Design a Distributed Job Scheduler →
• Design a sprint plannerLow-level design · reported at 1
  ● Meesho
• Design a stock market tick-stream system for millions of usersSystem design · reported at 1
  ● PaytmSQ-13 · Zerodha Kite Trading Platform →W08 · DAY 01 · Event Ingestion at Scale →W03 · DAY 03 · Backpressure and Flow Control →
• Design a Stock Price Alert SystemSystem design · reported at 1
  ● UberIP-06 · Design a Notification System →W03 · DAY 01 · Queue vs Stream →W06 · DAY 03 · Real-Time Channels: WebSockets and SSE at Scale →
• Design a Subscription and Usage-Based Billing CalculatorLow-level design · reported at 1
  ● StripeW08 · DAY 04 · Late-Arriving Data and Correctness →IP-20 · Design a Payment System →
• Design a subscription management systemSystem design · reported at 1
  ● PhonePeSQ-18 · Razorpay Payment Gateway →IP-17 · Design a Distributed Job Scheduler →
• Design a subscriptions platform for recurring paymentsSystem design · reported at 1
  ● RazorpaySQ-18 · Razorpay Payment Gateway →IP-20 · Design a Payment System →IP-17 · Design a Distributed Job Scheduler →
• Design a Support Ticket-Raising Application (LLD)Low-level design · reported at 1
  ● ZohoW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →
• Design a system that assigns drivers to ordersLow-level design · reported at 1
  ● SwiggySQ-17 · Swiggy Food Delivery →IP-13 · Design a Proximity Service →
• Design a Targeted Marketing Campaign EngineSystem design · reported at 1
  ● NykaaW06 · DAY 01 · Designing a Real-Time Notification Platform →W06 · DAY 03 · Real-Time Channels: WebSockets and SSE at Scale →W08 · DAY 02 · Streaming vs Batch Processing →
• Design a Task Manager Application (LLD)Low-level design · reported at 1
  ● Zoho
• Design a Task Manager that Evicts the Least Frequent Tasks (LLD)Low-level design · reported at 1
  ● Urban CompanyLLD-02 · Design an LRU Cache →
• Design a Task Scheduler (LLD)Low-level design · reported at 1
  ● OracleIP-17 · Design a Distributed Job Scheduler →W02 · DAY 05 · Distributed Cron & Job Scheduling →
• Design a task tracker with an activity logLow-level design · reported at 1
  ● PhonePeW03 · DAY 05 · Audit Log System →
• Design a thread-safe lock/unlock treeLow-level design · reported at 1
  ● JuspayW05 · DAY 05 · Leader Election and Coordination →W00 · PART 5 · Operating System Concepts for System Design →
• Design a Threaded Comment System like YouTube'sSystem design · reported at 1
  ● JioHotstarSQ-19 · YouTube Video Platform →W04 · DAY 04 · Feed Caching →
• Design a train booking system like IRCTCSystem design · reported at 1
  ● OlaSQ-11 · IRCTC Tatkal Ticket Booking System →LLD-05 · Design a Movie Ticket Booking System →
• Design a train ticket booking systemSystem design · reported at 1
  ● SwiggySQ-11 · IRCTC Tatkal Ticket Booking System →LLD-05 · Design a Movie Ticket Booking System →
• Design a Train Ticket Booking System like IRCTCSystem design · reported at 1
  ● MakeMyTripSQ-11 · IRCTC Tatkal Ticket Booking System →SQ-16 · BookMyShow Seat Booking →
• Design a travel booking service like Cleartrip with premium membershipSystem design · reported at 1
  ● PaytmIP-19 · Design a Hotel Reservation System →W04 · DAY 05 · Multi-Tier Caching →
• Design a Unified User Profile Fed by Many Teams (LLD)Low-level design · reported at 1
  ● JioHotstarW08 · DAY 03 · Data Modeling for Analytics →W08 · DAY 02 · Streaming vs Batch Processing →
• Design a UPI-like payment app (LLD)Low-level design · reported at 1
  ● PaytmSQ-01 · India's UPI →IP-20 · Design a Payment System →
• Design a URL RouterLow-level design · reported at 1
  ● Atlassian
• Design a Voting and Ranking SystemLow-level design · reported at 1
  ● AtlassianIP-14 · Design a Real-Time Leaderboard →
• Design a warehouse management system for InstamartSystem design · reported at 1
  ● SwiggySQ-12 · Blinkit Quick Commerce →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →W03 · DAY 02 · Transactional Outbox →
• Design a Weather App that Aggregates Third-Party ProvidersSystem design · reported at 1
  ● PostmanW04 · DAY 01 · Caching Patterns →W02 · DAY 03 · Circuit Breakers →IP-06 · Design a Notification System →
• Design a Workflow OrchestratorLow-level design · reported at 1
  ● Walmart Global TechW05 · DAY 03 · Saga Orchestration Deep Dive →IP-17 · Design a Distributed Job Scheduler →
• Design a Workflow Service for Cloud Resource ProvisioningSystem design · reported at 1
  ● OracleW05 · DAY 03 · Saga Orchestration Deep Dive →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →
• Design an Ad Frequency Capping SystemSystem design · reported at 1
  ● NetflixW01 · DAY 03 · Rate Limiting at Scale →W08 · DAY 01 · Event Ingestion at Scale →IP-16 · Design an Ad Click Aggregation System →
• Design an Ad Moderation PipelineSystem design · reported at 1
  ● MetaW03 · DAY 04 · Dead Letters and Poison Pills →W03 · DAY 01 · Queue vs Stream →W08 · DAY 02 · Streaming vs Batch Processing →
• Design an ad pacing service for restaurant campaignsSystem design · reported at 1
  ● ZomatoIP-16 · Design an Ad Click Aggregation System →W01 · DAY 03 · Rate Limiting at Scale →
• Design an ad serviceSystem design · reported at 1
  ● MeeshoIP-16 · Design an Ad Click Aggregation System →
• Design an Ad-Playback Analytics PipelineSystem design · reported at 1
  ● JioHotstarW08 · DAY 01 · Event Ingestion at Scale →IP-16 · Design an Ad Click Aggregation System →W08 · BOSS · Real-Time Analytics for Video Streaming Platform →
• Design an Airline Ticket Management SystemLow-level design · reported at 1
  ● FlipkartLLD-05 · Design a Movie Ticket Booking System →SQ-11 · IRCTC Tatkal Ticket Booking System →
• Design an Alerting System (LLD)Low-level design · reported at 1
  ● MakeMyTripIP-15 · Design a Metrics Monitoring and Alerting System →LLD-08 · Design a Logging Framework (Pub-Sub) →
• Design an API that counts orders in the last X minutesSystem design · reported at 1
  ● ZomatoIP-16 · Design an Ad Click Aggregation System →W08 · DAY 02 · Streaming vs Batch Processing →
• Design an app version management systemLow-level design · reported at 1
  ● PhonePeW10 · DAY 03 · Deployment Strategies →
• Design an ATM (LLD)Low-level design · reported at 1
  ● Urban Company
• Design an e-commerce applicationSystem design · reported at 1
  ● GrowwW04 · BOSS · Design a Global E-Commerce Product Catalog System →W03 · BOSS · Event-Driven Food Delivery Order System →
• Design an E-commerce Store (LLD)Low-level design · reported at 1
  ● PayPalW04 · BOSS · Design a Global E-Commerce Product Catalog System →
• Design an E-commerce WebsiteSystem design · reported at 1
  ● IntuitW04 · BOSS · Design a Global E-Commerce Product Catalog System →W03 · BOSS · Event-Driven Food Delivery Order System →
• Design an Employee On-Call Roster System like PagerDuty (LLD)Low-level design · reported at 1
  ● Freshworks
• Design an ETA calculator by vehicle typeLow-level design · reported at 1
  ● Paytm
• Design an In-Memory Cache with TTLLow-level design · reported at 1
  ● NetflixLLD-02 · Design an LRU Cache →W04 · DAY 02 · Invalidation Strategies →
• Design an in-memory databaseLow-level design · reported at 1
  ● CREDIP-03 · Design a Distributed Key-Value Store →
• Design an In-Memory Event Store for Real-Time QueriesLow-level design · reported at 1
  ● AppleLLD-08 · Design a Logging Framework (Pub-Sub) →W08 · DAY 03 · Data Modeling for Analytics →
• Design an In-Memory Key-Value Store with Transactions (LLD)Low-level design · reported at 1
  ● ZohoIP-03 · Design a Distributed Key-Value Store →W05 · DAY 01 · Consistency Models →
• Design an in-memory search engine for blog contentLow-level design · reported at 1
  ● RazorpayW07 · DAY 02 · Indexing Pipeline →W07 · DAY 01 · Search Fundamentals & Architecture →
• Design an in-memory wallet and ledgerLow-level design · reported at 1
  ● GrowwIP-20 · Design a Payment System →W03 · DAY 05 · Audit Log System →
• Design an internal app to track driversSystem design · reported at 1
  ● OlaIP-13 · Design a Proximity Service →SQ-09 · Uber →
• Design an interview slot allocation systemLow-level design · reported at 1
  ● FlipkartLLD-05 · Design a Movie Ticket Booking System →
• Design an intraday auto square-off risk serviceSystem design · reported at 1
  ● GrowwSQ-13 · Zerodha Kite Trading Platform →W08 · DAY 01 · Event Ingestion at Scale →W02 · DAY 02 · Idempotency in Practice →
• Design an inventory management system for InstamartLow-level design · reported at 1
  ● SwiggySQ-12 · Blinkit Quick Commerce →W02 · BOSS · The Ultimate System Design Interview →
• Design an Invoice and Commission SystemSystem design · reported at 1
  ● IntuitIP-20 · Design a Payment System →W08 · DAY 03 · Data Modeling for Analytics →
• Design an Offline-Capable Payment SystemSystem design · reported at 1
  ● AppleIP-20 · Design a Payment System →W05 · DAY 04 · Conflict Resolution →W09 · DAY 05 · Security Architecture →
• Design an Online Auction SystemSystem design · reported at 1
  ● IntuitW01 · DAY 04 · Hot Keys and Skew →W05 · DAY 01 · Consistency Models →IP-14 · Design a Real-Time Leaderboard →
• Design an Online Judge (LeetCode)System design · reported at 1
  ● MetaW03 · DAY 01 · Queue vs Stream →W09 · DAY 02 · Noisy Neighbor Prevention →IP-14 · Design a Real-Time Leaderboard →
• Design an orchestration serviceLow-level design · reported at 1
  ● ShareChatW05 · DAY 03 · Saga Orchestration Deep Dive →
• Design an order and inventory management serviceLow-level design · reported at 1
  ● MeeshoSQ-12 · Blinkit Quick Commerce →W02 · BOSS · The Ultimate System Design Interview →
• Design API monetisation with subscription plansSystem design · reported at 1
  ● GrowwW01 · DAY 03 · Rate Limiting at Scale →W09 · DAY 02 · Noisy Neighbor Prevention →
• Design book searchSystem design · reported at 1
  ● SwiggyW07 · DAY 01 · Search Fundamentals & Architecture →IP-09 · Design Typeahead Search (Autocomplete) →
• Design Browser History (LLD)Low-level design · reported at 1
  ● Zoho
• Design Comments, Likes and FollowsSystem design · reported at 1
  ● SalesforceIP-07 · Design a News Feed →W01 · DAY 04 · Hot Keys and Skew →
• Design Curbside PickupSystem design · reported at 1
  ● Walmart Global TechIP-06 · Design a Notification System →IP-13 · Design a Proximity Service →
• Design DNSSystem design · reported at 1
  ● AppleW00 · PART 4 · Networking Fundamentals for System Design →W04 · DAY 05 · Multi-Tier Caching →
• Design group chat with admin rulesLow-level design · reported at 1
  ● GrowwIP-08 · Design a Chat System →
• Design lineup notifications sent before a match startsSystem design · reported at 1
  ● Dream11IP-06 · Design a Notification System →W06 · DAY 04 · Presence and Chat Fan-Out at Scale →W01 · DAY 04 · Hot Keys and Skew →
• Design Live CommentsSystem design · reported at 1
  ● MetaIP-08 · Design a Chat System →W04 · DAY 04 · Feed Caching →W03 · DAY 03 · Backpressure and Flow Control →
• Design Microservices for an E-commerce SystemSystem design · reported at 1
  ● Morgan StanleyW03 · BOSS · Event-Driven Food Delivery Order System →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →W04 · BOSS · Design a Global E-Commerce Product Catalog System →
• Design order management and payments for a shipping platform like ShiprocketSystem design · reported at 1
  ● PaytmW03 · BOSS · Event-Driven Food Delivery Order System →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →IP-20 · Design a Payment System →
• Design PastebinSystem design · reported at 1
  ● AmazonIP-12 · Design Pastebin →SQ-08 · AWS S3 →
• Design People You May KnowSystem design · reported at 1
  ● LinkedInW08 · DAY 02 · Streaming vs Batch Processing →W01 · DAY 01 · Partitioning Deep-Dive →
• Design Restaurant Search for a Food Delivery AppLow-level design · reported at 1
  ● SalesforceW07 · DAY 03 · Query Processing & Relevance →SQ-17 · Swiggy Food Delivery →
• Design ride poolingSystem design · reported at 1
  ● OlaSQ-09 · Uber →IP-13 · Design a Proximity Service →
• Design SIP creation and scheduled transactionsLow-level design · reported at 1
  ● GrowwIP-17 · Design a Distributed Job Scheduler →W02 · DAY 02 · Idempotency in Practice →
• Design Stack OverflowLow-level design · reported at 1
  ● SalesforceW07 · DAY 01 · Search Fundamentals & Architecture →W07 · DAY 02 · Indexing Pipeline →
• Design the Database for a Social Media App (LLD)Low-level design · reported at 1
  ● NykaaIP-07 · Design a News Feed →W08 · DAY 03 · Data Modeling for Analytics →
• Design the Database Schema for a Chat SystemLow-level design · reported at 1
  ● MakeMyTripIP-08 · Design a Chat System →SQ-02 · WhatsApp Messaging →
• Design the Database Schema for TwitterSystem design · reported at 1
  ● BrowserStackSQ-10 · Twitter/X →W01 · DAY 01 · Partitioning Deep-Dive →
• Design the microservices for a fashion e-commerce appSystem design · reported at 1
  ● MyntraW04 · BOSS · Design a Global E-Commerce Product Catalog System →W03 · BOSS · Event-Driven Food Delivery Order System →
• Design the schema for delivery partners and ordersSystem design · reported at 1
  ● ZomatoSQ-17 · Swiggy Food Delivery →W06 · BOSS · Food Delivery Order System →
• Design Top-K Frequent Items in a StreamConcept · reported at 1
  ● AdobeIP-16 · Design an Ad Click Aggregation System →W08 · DAY 02 · Streaming vs Batch Processing →
• Design Top-K Trending ArticlesSystem design · reported at 1
  ● LinkedInIP-16 · Design an Ad Click Aggregation System →W08 · DAY 02 · Streaming vs Batch Processing →IP-14 · Design a Real-Time Leaderboard →
• Design Twitter (LLD)Low-level design · reported at 1
  ● IntuitSQ-10 · Twitter/X →IP-07 · Design a News Feed →
• Design Undo for Deleted Collections with a TTLLow-level design · reported at 1
  ● PostmanW09 · DAY 04 · Right to Deletion →
• Design Video View Counts and Watch HistorySystem design · reported at 1
  ● JioHotstarIP-16 · Design an Ad Click Aggregation System →W01 · DAY 04 · Hot Keys and Skew →SQ-19 · YouTube Video Platform →
• Explain Kafka's architecture and componentsConcept · reported at 1
  ● MyntraW03 · DAY 01 · Queue vs Stream →IP-18 · Design a Distributed Message Queue →
• Find the Top K Users Logging In Each Day at Millions of LoginsSystem design · reported at 1
  ● JPMorgan ChaseIP-14 · Design a Real-Time Leaderboard →IP-16 · Design an Ad Click Aggregation System →W01 · DAY 04 · Hot Keys and Skew →
• How do circuit breakers make services resilient?Concept · reported at 1
  ● MyntraW02 · DAY 03 · Circuit Breakers →W02 · DAY 01 · Timeout Hell →
• How do Kafka partitions affect ordering and consumer idempotency?Concept · reported at 1
  ● ZomatoW03 · DAY 01 · Queue vs Stream →W02 · DAY 02 · Idempotency in Practice →
• How do you deprecate a feature while rolling out its replacement to clients?Concept · reported at 1
  ● InMobiW10 · DAY 03 · Deployment Strategies →
• How do you find a performance issue in production?Concept · reported at 1
  ● Morgan StanleyW10 · DAY 02 · Observability →W10 · DAY 05 · Incident Management →
• How do you remove duplicate lines from a 10 GB file with 2 GB of memory?Concept · reported at 1
  ● Morgan StanleyW08 · DAY 02 · Streaming vs Batch Processing →W01 · DAY 01 · Partitioning Deep-Dive →
• How do you send a push notification to one specific device?Concept · reported at 1
  ● RapidoW06 · DAY 02 · The Delivery Pipeline: Guarantees, Priorities and Preferences →IP-06 · Design a Notification System →
• How do you serve 500k records to a browser efficiently?Concept · reported at 1
  ● JPMorgan ChaseW04 · DAY 01 · Caching Patterns →W07 · DAY 05 · Location Search and Search at Scale →
• How does a hash table work internally, and how do you make it thread-safe?Concept · reported at 1
  ● InMobiW00 · PART 5 · Operating System Concepts for System Design →
• How does a load balancer work?Concept · reported at 1
  ● SprinklrW00 · PART 2 · Infrastructure Building Blocks →W00 · PART 4 · Networking Fundamentals for System Design →
• How does change data capture work?Concept · reported at 1
  ● Dream11W03 · DAY 02 · Transactional Outbox →
• How does consistent hashing work?Concept · reported at 1
  ● FreshworksW01 · DAY 01 · Partitioning Deep-Dive →IP-03 · Design a Distributed Key-Value Store →
• How does OS process scheduling work?Concept · reported at 1
  ● JuspayW00 · PART 5 · Operating System Concepts for System Design →
• How would you count the words in a very large file efficiently?Concept · reported at 1
  ● BrowserStackW08 · DAY 02 · Streaming vs Batch Processing →W00 · PART 5 · Operating System Concepts for System Design →
• How would you find every text file that contains a given word?Concept · reported at 1
  ● SprinklrW07 · DAY 01 · Search Fundamentals & Architecture →W07 · DAY 02 · Indexing Pipeline →
• How would you host a website without any external service?Concept · reported at 1
  ● BrowserStackW00 · PART 4 · Networking Fundamentals for System Design →W00 · PART 2 · Infrastructure Building Blocks →
• How would you prepare your system for the IPL?Concept · reported at 1
  ● Dream11W10 · DAY 04 · Capacity Planning →W10 · DAY 03 · Deployment Strategies →
• How would you send a large sorted stream of numbers efficiently from an API?Concept · reported at 1
  ● Morgan StanleyW00 · PART 4 · Networking Fundamentals for System Design →W03 · DAY 03 · Backpressure and Flow Control →
• Implement a lock without mutexes, semaphores or atomicsConcept · reported at 1
  ● JuspayW00 · PART 5 · Operating System Concepts for System Design →
• Implement a Producer-Consumer QueueLow-level design · reported at 1
  ● Morgan StanleyW03 · DAY 03 · Backpressure and Flow Control →W00 · PART 5 · Operating System Concepts for System Design →
• Implement a Queueing Service as a LibraryLow-level design · reported at 1
  ● JioHotstarIP-18 · Design a Distributed Message Queue →LLD-08 · Design a Logging Framework (Pub-Sub) →
• Implement an In-Memory Cache like Redis in Java (LLD)Low-level design · reported at 1
  ● ZohoLLD-02 · Design an LRU Cache →IP-11 · Design a Distributed Cache →
• Isolation levels and pessimistic vs optimistic lockingConcept · reported at 1
  ● Dream11W05 · DAY 01 · Consistency Models →
• MongoDB or Postgres, and what is the finest grain of concurrency control in a database?Concept · reported at 1
  ● Morgan StanleyW05 · DAY 01 · Consistency Models →W00 · PART 2 · Infrastructure Building Blocks →
• Monolith or microservices, and should each microservice own its database?Concept · reported at 1
  ● RapidoW00 · PART 1 · System Design Fundamentals →W03 · DAY 02 · Transactional Outbox →
• Networking fundamentals deep diveConcept · reported at 1
  ● JuspayW00 · PART 4 · Networking Fundamentals for System Design →
• Parse JSON from a URL and answer count queriesLow-level design · reported at 1
  ● Ola
• Pessimistic vs optimistic locking and transaction isolation levelsConcept · reported at 1
  ● PaytmW05 · DAY 01 · Consistency Models →
• Scale a Monolith to 50x Traffic and Integrate a Prediction ServiceSystem design · reported at 1
  ● JPMorgan ChaseW10 · DAY 04 · Capacity Planning →W04 · DAY 01 · Caching Patterns →W02 · DAY 03 · Circuit Breakers →
• Sharding, SQL vs NoSQL, and ACID vs CAPConcept · reported at 1
  ● PaytmW01 · DAY 01 · Partitioning Deep-Dive →W00 · PART 6 · System Design Terminology & Theory →
• Sort petabytes of data spread across 10,000 disksSystem design · reported at 1
  ● ShareChatW08 · DAY 02 · Streaming vs Batch Processing →W01 · DAY 01 · Partitioning Deep-Dive →
• SQL or NoSQL, and when does an index not help?Concept · reported at 1
  ● RapidoW00 · PART 2 · Infrastructure Building Blocks →W00 · PART 6 · System Design Terminology & Theory →
• What changes when you take a production app beyond one country?Concept · reported at 1
  ● AtlassianW09 · DAY 03 · Data Residency and GDPR →W01 · DAY 02 · Replication Trade-offs →
• What goes wrong in a master-slave setup, and how do you debug it?Concept · reported at 1
  ● InMobiW01 · DAY 02 · Replication Trade-offs →W05 · DAY 05 · Leader Election and Coordination →
• What happens when Kafka consumers lag behind producers?Concept · reported at 1
  ● ZomatoW03 · DAY 03 · Backpressure and Flow Control →W03 · DAY 01 · Queue vs Stream →
• What is horizontal versus vertical scaling?Concept · reported at 1
  ● RapidoW00 · PART 1 · System Design Fundamentals →W10 · DAY 04 · Capacity Planning →
• What problems does consistent hashing leave unsolved?Concept · reported at 1
  ● AtlassianW01 · DAY 01 · Partitioning Deep-Dive →W01 · DAY 04 · Hot Keys and Skew →
• When would you use Kafka versus SNS, and how do you design retries?Concept · reported at 1
  ● NykaaW03 · DAY 01 · Queue vs Stream →W03 · DAY 04 · Dead Letters and Poison Pills →W02 · DAY 01 · Timeout Hell →
• Which database would you choose for large volumes of unstructured data?Concept · reported at 1
  ● JPMorgan ChaseW00 · PART 2 · Infrastructure Building Blocks →W00 · PART 6 · System Design Terminology & Theory →
• Why is Redis fast while being single-threaded?Concept · reported at 1
  ● ZomatoIP-11 · Design a Distributed Cache →W04 · DAY 01 · Caching Patterns →
• Write a Client Library Wrapping the BrowserStack REST APILow-level design · reported at 1
  ● BrowserStackW02 · DAY 01 · Timeout Hell →W02 · DAY 02 · Idempotency in Practice →
• Design an E-commerce Flash SaleSystem design
  ○ Amazon○ CRED○ Flipkart○ Myntra○ Nykaa○ Walmart Global TechW02 · BOSS · The Ultimate System Design Interview →W01 · DAY 04 · Hot Keys and Skew →W04 · DAY 03 · Thundering Herd →
• Design a Multi-Tenant SaaS PlatformSystem design
  ○ Adobe○ Atlassian○ Intuit○ SalesforceW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →W09 · DAY 02 · Noisy Neighbor Prevention →W09 · DAY 01 · Tenant Isolation Strategies →
• Design an Ad Click Aggregation SystemSystem design
  ○ InMobi○ Meta○ ShareChatIP-16 · Design an Ad Click Aggregation System →W08 · DAY 04 · Late-Arriving Data and Correctness →
• Design an e-commerce product catalogue and searchSystem design
  ○ Flipkart○ Meesho○ MyntraW04 · BOSS · Design a Global E-Commerce Product Catalog System →W07 · DAY 01 · Search Fundamentals & Architecture →W07 · DAY 03 · Query Processing & Relevance →
• Design live market-data streaming to millions of clientsSystem design
  ○ Groww○ ZerodhaSQ-13 · Zerodha Kite Trading Platform →W03 · DAY 03 · Backpressure and Flow Control →W08 · DAY 01 · Event Ingestion at Scale →
• Design webhook delivery with retriesSystem design
  ○ Juspay○ RazorpayW02 · DAY 04 · Webhook Delivery System →W03 · DAY 04 · Dead Letters and Poison Pills →
• Design a Captain Wallet and Daily PayoutsSystem design
  ○ RapidoIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →W03 · DAY 05 · Audit Log System →
• Design a Card Payment NetworkSystem design
  ○ StripeSQ-04 · Visa/Mastercard Global Payment Network →IP-20 · Design a Payment System →
• Design a card tokenisation vaultSystem design
  ○ JuspayW09 · DAY 05 · Security Architecture →SQ-04 · Visa/Mastercard Global Payment Network →
• Design a Cloud Device Farm that Allocates Real Browsers and Phones to Test SessionsSystem design
  ○ BrowserStackW09 · DAY 02 · Noisy Neighbor Prevention →IP-17 · Design a Distributed Job Scheduler →W01 · DAY 05 · Session Store Design →
• Design a Double-Entry LedgerSystem design
  ○ StripeIP-20 · Design a Payment System →W03 · DAY 05 · Audit Log System →W03 · DAY 02 · Transactional Outbox →
• Design a Hotel Reservation SystemSystem design
  ○ MakeMyTripIP-19 · Design a Hotel Reservation System →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →
• Design a Multi-Tenant CRM PlatformSystem design
  ○ ZohoW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →W09 · DAY 01 · Tenant Isolation Strategies →W09 · DAY 03 · Data Residency and GDPR →
• Design a Multi-Tenant Helpdesk Ticketing SystemSystem design
  ○ FreshworksW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →W09 · DAY 01 · Tenant Isolation Strategies →W09 · DAY 02 · Noisy Neighbor Prevention →
• Design a payment router across multiple gatewaysSystem design
  ○ JuspaySQ-18 · Razorpay Payment Gateway →W02 · DAY 03 · Circuit Breakers →W02 · DAY 01 · Timeout Hell →
• Design a Personalised Lock-Screen Content FeedSystem design
  ○ InMobiIP-07 · Design a News Feed →W04 · DAY 04 · Feed Caching →SQ-21 · Instagram Feed and Stories →
• Design a Product CatalogSystem design
  ○ Walmart Global TechW04 · BOSS · Design a Global E-Commerce Product Catalog System →W04 · DAY 02 · Invalidation Strategies →
• Design a Product Catalog with Search and FiltersSystem design
  ○ NykaaW04 · BOSS · Design a Global E-Commerce Product Catalog System →W07 · DAY 01 · Search Fundamentals & Architecture →W07 · DAY 04 · Typeahead at Scale: Autocomplete, Spelling and Facets →
• Design a Real-Time Bidding Ad ServerSystem design
  ○ InMobiW02 · DAY 01 · Timeout Hell →W04 · DAY 05 · Multi-Tier Caching →W01 · DAY 04 · Hot Keys and Skew →
• Design a Real-Time Market Data Distribution SystemSystem design
  ○ Morgan StanleyW03 · DAY 01 · Queue vs Stream →W03 · DAY 03 · Backpressure and Flow Control →SQ-13 · Zerodha Kite Trading Platform →
• Design a rewards points ledgerSystem design
  ○ CREDW03 · DAY 05 · Audit Log System →W03 · DAY 02 · Transactional Outbox →
• Design a Scheduled API Monitoring ServiceSystem design
  ○ PostmanIP-17 · Design a Distributed Job Scheduler →IP-15 · Design a Metrics Monitoring and Alerting System →W09 · DAY 02 · Noisy Neighbor Prevention →
• Design a Search EngineSystem design
  ○ GoogleSQ-05 · Google Search →W07 · DAY 03 · Query Processing & Relevance →IP-05 · Design a Web Crawler →
• Design a session store with two-factor loginSystem design
  ○ ZerodhaW01 · DAY 05 · Session Store Design →W09 · DAY 05 · Security Architecture →
• Design a short-video feed like MojSystem design
  ○ ShareChatSQ-21 · Instagram Feed and Stories →SQ-19 · YouTube Video Platform →
• Design a Social Listening Pipeline that Ingests Posts from Many NetworksSystem design
  ○ SprinklrW08 · DAY 01 · Event Ingestion at Scale →W03 · DAY 03 · Backpressure and Flow Control →W07 · DAY 02 · Indexing Pipeline →
• Design a Surge Pricing EngineSystem design
  ○ RapidoW08 · DAY 02 · Streaming vs Batch Processing →SQ-09 · Uber →
• Design a Tamper-Evident Transaction Audit LogSystem design
  ○ JPMorgan ChaseW03 · DAY 05 · Audit Log System →W09 · DAY 05 · Security Architecture →
• Design a Test Logs and Results PipelineSystem design
  ○ BrowserStackW08 · DAY 01 · Event Ingestion at Scale →W10 · DAY 02 · Observability →SQ-08 · AWS S3 →
• Design a Unified Customer-Care Inbox with Agent RoutingSystem design
  ○ SprinklrW09 · BOSS · Design a Multi-Tenant Enterprise SaaS Platform →IP-08 · Design a Chat System →W03 · DAY 01 · Queue vs Stream →
• Design a Video Viewing Analytics PipelineSystem design
  ○ NetflixW08 · BOSS · Real-Time Analytics for Video Streaming Platform →W08 · DAY 02 · Streaming vs Batch Processing →W08 · DAY 04 · Late-Arriving Data and Correctness →
• Design a Web Analytics PipelineSystem design
  ○ AdobeW08 · DAY 01 · Event Ingestion at Scale →W08 · DAY 03 · Data Modeling for Analytics →W08 · DAY 05 · Query Layer and Optimization →
• Design Ad Frequency Capping and Budget PacingSystem design
  ○ InMobiW01 · DAY 03 · Rate Limiting at Scale →IP-16 · Design an Ad Click Aggregation System →
• Design an API GatewaySystem design
  ○ ZerodhaW09 · DAY 05 · Security Architecture →W09 · DAY 02 · Noisy Neighbor Prevention →
• Design an Audit Log SystemSystem design
  ○ Goldman SachsW03 · DAY 05 · Audit Log System →W09 · DAY 05 · Security Architecture →
• Design an Email Service like Zoho MailSystem design
  ○ ZohoW06 · DAY 01 · Designing a Real-Time Notification Platform →W07 · DAY 02 · Indexing Pipeline →IP-10 · Design a File Sync Service (Dropbox / Google Drive) →
• Design an Object Storage ServiceSystem design
  ○ OracleSQ-08 · AWS S3 →IP-03 · Design a Distributed Key-Value Store →W01 · DAY 02 · Replication Trade-offs →
• Design contest joining before the match deadlineSystem design
  ○ Dream11W02 · BOSS · The Ultimate System Design Interview →W01 · DAY 04 · Hot Keys and Skew →W03 · DAY 03 · Backpressure and Flow Control →
• Design credit card bill payments with remindersSystem design
  ○ CREDIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →IP-06 · Design a Notification System →
• Design end-of-day reconciliation and contract-note generationSystem design
  ○ ZerodhaW08 · DAY 02 · Streaming vs Batch Processing →W02 · DAY 05 · Distributed Cron & Job Scheduling →W03 · DAY 05 · Audit Log System →
• Design Flight Search with Cached Fares from Many SuppliersSystem design
  ○ MakeMyTripW04 · DAY 02 · Invalidation Strategies →W04 · DAY 05 · Multi-Tier Caching →W02 · DAY 01 · Timeout Hell →
• Design idempotent payment APIsConcept
  ○ JuspayW02 · DAY 02 · Idempotency in Practice →
• Design Inventory Reservation across Warehouses and StoresSystem design
  ○ NykaaW05 · DAY 02 · Distributed Transactions — The Saga Pattern →W03 · DAY 02 · Transactional Outbox →SQ-12 · Blinkit Quick Commerce →
• Design Live Captain Location Tracking and ETASystem design
  ○ RapidoSQ-09 · Uber →W08 · DAY 01 · Event Ingestion at Scale →W03 · DAY 03 · Backpressure and Flow Control →
• Design live score and points updates for millions of usersSystem design
  ○ Dream11W04 · DAY 04 · Feed Caching →W08 · DAY 02 · Streaming vs Batch Processing →
• Design Live Streaming of a Cricket Match to Tens of Millions of ViewersSystem design
  ○ JioHotstarSQ-06 · Netflix Streaming →W04 · DAY 03 · Thundering Herd →W10 · DAY 04 · Capacity Planning →
• Design Live Streaming of a Remote Browser Session to the UserSystem design
  ○ BrowserStackW03 · DAY 03 · Backpressure and Flow Control →W00 · PART 4 · Networking Fundamentals for System Design →
• Design Matching of Home-Service Professionals to BookingsSystem design
  ○ Urban CompanyIP-13 · Design a Proximity Service →SQ-09 · Uber →W05 · DAY 01 · Consistency Models →
• Design order placement that survives the market-open spikeSystem design
  ○ ZerodhaSQ-13 · Zerodha Kite Trading Platform →W01 · DAY 04 · Hot Keys and Skew →W02 · DAY 01 · Timeout Hell →
• Design portfolio and P&L reports over years of tradesSystem design
  ○ ZerodhaW08 · DAY 03 · Data Modeling for Analytics →W08 · DAY 05 · Query Layer and Optimization →W01 · DAY 01 · Partitioning Deep-Dive →
• Design price alerts and good-till-triggered ordersSystem design
  ○ ZerodhaIP-17 · Design a Distributed Job Scheduler →IP-06 · Design a Notification System →
• Design Real-Time Card Fraud DetectionSystem design
  ○ JPMorgan ChaseW08 · DAY 02 · Streaming vs Batch Processing →SQ-04 · Visa/Mastercard Global Payment Network →W02 · DAY 01 · Timeout Hell →
• Design recurring mutual fund SIP ordersSystem design
  ○ ZerodhaIP-17 · Design a Distributed Job Scheduler →W02 · DAY 02 · Idempotency in Practice →
• Design Scheduled Publishing to Social NetworksSystem design
  ○ SprinklrIP-17 · Design a Distributed Job Scheduler →W01 · DAY 03 · Rate Limiting at Scale →W02 · DAY 04 · Webhook Delivery System →
• Design Slot Availability and Booking for Service ProfessionalsSystem design
  ○ Urban CompanyIP-19 · Design a Hotel Reservation System →SQ-16 · BookMyShow Seat Booking →W02 · DAY 02 · Idempotency in Practice →
• Design surge pricingSystem design
  ○ OlaSQ-09 · Uber →W08 · DAY 02 · Streaming vs Batch Processing →
• Design telemetry ingestion for connected electric scootersSystem design
  ○ OlaW08 · DAY 01 · Event Ingestion at Scale →IP-15 · Design a Metrics Monitoring and Alerting System →W08 · DAY 04 · Late-Arriving Data and Correctness →
• Design Workspace Sync for Shared API CollectionsSystem design
  ○ PostmanIP-10 · Design a File Sync Service (Dropbox / Google Drive) →W05 · DAY 04 · Conflict Resolution →
• How do circuit breakers and fallbacks keep a microservice platform up?Concept
  ○ NetflixW02 · DAY 03 · Circuit Breakers →W02 · DAY 01 · Timeout Hell →
• How do idempotency keys make payment API retries safe?Concept
  ○ StripeW02 · DAY 02 · Idempotency in Practice →W02 · DAY 01 · Timeout Hell →
• How would you roll out a change safely across regions?Concept
  ○ NetflixW10 · DAY 03 · Deployment Strategies →W10 · DAY 05 · Incident Management →