System design interview questions test your ability to design distributed systems at scale. Expect questions on API design, data modeling, caching strategies, database trade-offs, queueing systems, and how you handle consistency, availability, and partition tolerance.
Backend / Distributed System Design Questions (13)
Design distributed backend systems like URL shorteners, social feeds, chat apps, and notification platforms. Show clear trade-offs and architecture decisions.
medium Design a URL shortener (like Bitly)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a social media feed (like Twitter/X)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a video streaming service (like YouTube/Netflix)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a chat application (like Telegram, Slack, Discord)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a file sharing/storage service (like Google Drive, Dropbox)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a ride sharing service (like Uber, Lyft)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a photo sharing service (like Flickr, Pinterest, Instagram)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design an e-commerce platform (like Amazon, eBay)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a jobs portal (like LinkedIn, Indeed)
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a web crawler (like Google)
What interviewers evaluate: Backend / Distributed System Design Questions
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medium Design a rate limiter
What interviewers evaluate: Backend / Distributed System Design Questions
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medium Design a notification system
What interviewers evaluate: Backend / Distributed System Design Questions
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hard Design a news feed ranking system
What interviewers evaluate: Backend / Distributed System Design Questions
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UI Component Design (5)
Design reusable UI components like autocomplete, image carousels, dropdown menus, and rich text editors. Cover state management, accessibility, and edge cases.
medium Design an Autocomplete component
What interviewers evaluate: UI Component Design
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medium Design an Image Carousel
What interviewers evaluate: UI Component Design
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medium Design a Dropdown Menu
What interviewers evaluate: UI Component Design
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medium Design a Modal Dialog
What interviewers evaluate: UI Component Design
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hard Design a Rich Text Editor
What interviewers evaluate: UI Component Design
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Application Design (8)
Design end-to-end applications like Facebook News Feed, Instagram, Pinterest, and Google Docs. Show how you handle data flow, state, and user interactions.
hard Design a News Feed (like Facebook)
What interviewers evaluate: Application Design
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hard Design an E-commerce marketplace frontend
What interviewers evaluate: Application Design
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hard Design a Chat application frontend (like Messenger)
What interviewers evaluate: Application Design
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hard Design a Photo sharing app frontend (like Instagram)
What interviewers evaluate: Application Design
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medium Design a Pinterest-style layout
What interviewers evaluate: Application Design
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hard Design a Collaborative editor (like Google Docs)
What interviewers evaluate: Application Design
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hard Design a Travel booking frontend (like Airbnb)
What interviewers evaluate: Application Design
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hard Design a Video streaming frontend (like Netflix)
What interviewers evaluate: Application Design
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Infrastructure & Distributed Systems (10)
Design infrastructure components like distributed caches, job schedulers, pub/sub systems, locking services, and the building blocks of large-scale systems.
medium Design a distributed cache (like Redis/Memcached)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a distributed task/job scheduler
What interviewers evaluate: Infrastructure & Distributed Systems
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medium Design a pub/sub messaging system (like Kafka)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a distributed locking service (like Google Chubby/ZooKeeper)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a coordination service (like ZooKeeper)
What interviewers evaluate: Infrastructure & Distributed Systems
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medium Design a distributed key-value store
What interviewers evaluate: Infrastructure & Distributed Systems
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medium Design a content delivery network (CDN)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a code deployment system (CI/CD pipeline)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a distributed storage system (like Google Bigtable/HBase)
What interviewers evaluate: Infrastructure & Distributed Systems
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hard Design a data structures system for a social network graph
What interviewers evaluate: Infrastructure & Distributed Systems
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Financial & Transactional Systems (6)
Design payment gateways, trading systems, ticketing platforms, and the financial systems where consistency, durability, and audit trails matter most.
hard Design a payment gateway system (like Stripe)
What interviewers evaluate: Financial & Transactional Systems
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hard Design a stock exchange/trading system
What interviewers evaluate: Financial & Transactional Systems
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medium Design a ticketing/booking system (concert/movie tickets)
What interviewers evaluate: Financial & Transactional Systems
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medium Design a flight booking system
What interviewers evaluate: Financial & Transactional Systems
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medium Design an ATM system
What interviewers evaluate: Financial & Transactional Systems
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medium Design a Unified Payments Interface (UPI)
What interviewers evaluate: Financial & Transactional Systems
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Social & Content Platforms (7)
Design social platforms like TikTok, Reddit, Spotify, and Tinder. Cover content delivery, recommendation systems, and high-engagement architectures.
hard Design TikTok (video-first social platform)
What interviewers evaluate: Social & Content Platforms
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medium Design Reddit/Quora (forum-based platform)
What interviewers evaluate: Social & Content Platforms
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medium Design Tinder (matching/dating app)
What interviewers evaluate: Social & Content Platforms
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hard Design Spotify (music streaming)
What interviewers evaluate: Social & Content Platforms
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hard Design a Bluesky-style decentralized social network
What interviewers evaluate: Social & Content Platforms
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hard Design Shopify (multi-tenant e-commerce)
What interviewers evaluate: Social & Content Platforms
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hard Design Airbnb (marketplace with booking)
What interviewers evaluate: Social & Content Platforms
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Search & Discovery Systems (3)
Design search engines, typeahead, autocomplete, and discovery features. Cover indexing, ranking, query parsing, and relevance at scale.
hard Design a search engine (like Google)
What interviewers evaluate: Search & Discovery Systems
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medium Design a typeahead/autocomplete system
What interviewers evaluate: Search & Discovery Systems
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hard Design Facebook/Twitter search
What interviewers evaluate: Search & Discovery Systems
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Gaming & Interactive Systems (3)
Design real-time multiplayer games, collaborative editors, and interactive systems where latency, state synchronization, and concurrent users matter.
hard Design a multiplayer online game
What interviewers evaluate: Gaming & Interactive Systems
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medium Design a chess/board game system
What interviewers evaluate: Gaming & Interactive Systems
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hard Design an online code editor (like CodeSandbox/Replit)
What interviewers evaluate: Gaming & Interactive Systems
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Security & Authentication Systems (3)
Design authentication systems, SSO platforms, rate limiters, and the security infrastructure that protects user data and prevents abuse.
medium Design an authentication and SSO platform (like Auth0/Okta)
What interviewers evaluate: Security & Authentication Systems
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hard Design an electronic voting system
What interviewers evaluate: Security & Authentication Systems
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medium Design an API rate limiter (detailed)
What interviewers evaluate: Security & Authentication Systems
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Real-Time & Monitoring Systems (4)
Design video conferencing, food delivery, analytics platforms, and the real-time systems that handle continuous data streams at scale.
hard Design a video conferencing system (like Zoom)
What interviewers evaluate: Real-Time & Monitoring Systems
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hard Design a food delivery system (like DoorDash/Uber Eats)
What interviewers evaluate: Real-Time & Monitoring Systems
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hard Design an analytics platform (like Mixpanel/Amplitude)
What interviewers evaluate: Real-Time & Monitoring Systems
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medium Design a traffic control system
What interviewers evaluate: Real-Time & Monitoring Systems
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AI/ML System Design (3)
Design AI-powered systems including conversational AI services, recommendation engines, and the inference infrastructure that serves ML models at scale.
hard Design an AI-powered customer support system
What interviewers evaluate: AI/ML System Design
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hard Design a ChatGPT-style conversational AI service
What interviewers evaluate: AI/ML System Design
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hard Design a recommendation system (ML focus)
What interviewers evaluate: AI/ML System Design
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Architecture & Decomposition (5)
Cover microservices decomposition, the Strangler Fig pattern, Domain-Driven Design, and the architectural decisions that determine long-term maintainability.
hard How would you decompose a monolithic application into microservices? What principles guide service boundaries?
What interviewers evaluate: Architecture & Decomposition
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hard What is the Strangler Fig pattern? How do you use it to migrate from monolith to microservices?
What interviewers evaluate: Architecture & Decomposition
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hard Explain Bounded Context from Domain-Driven Design. How does it define microservice boundaries?
What interviewers evaluate: Architecture & Decomposition
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medium What is the difference between orchestration and choreography in microservices? When do you use each?
What interviewers evaluate: Architecture & Decomposition
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medium How do you handle cross-cutting concerns (logging, auth, tracing) in a microservices architecture?
What interviewers evaluate: Architecture & Decomposition
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Inter-Service Communication (5)
Compare REST, gRPC, and message queues. Cover API gateways, service meshes, and the patterns for managing communication between many microservices.
medium Compare synchronous (REST/gRPC) vs asynchronous (message queue) communication between services. When do you use each?
What interviewers evaluate: Inter-Service Communication
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medium What is an API Gateway? What responsibilities should it handle? (routing, auth, rate limiting, aggregation)
What interviewers evaluate: Inter-Service Communication
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medium When would you choose gRPC over REST for inter-service communication?
What interviewers evaluate: Inter-Service Communication
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hard What is a service mesh (like Istio/Linkerd)? When would you introduce one?
What interviewers evaluate: Inter-Service Communication
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hard How would you handle communication between 50+ microservices without creating a tangled mess?
What interviewers evaluate: Inter-Service Communication
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Data Consistency & Transactions (5)
Cover the Saga pattern, CQRS, Event Sourcing, eventual consistency, and the strategies for maintaining data integrity across distributed services.
hard What is the Saga pattern? Compare orchestration-based vs choreography-based sagas.
What interviewers evaluate: Data Consistency & Transactions
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hard Explain CQRS (Command Query Responsibility Segregation). When is it worth the complexity?
What interviewers evaluate: Data Consistency & Transactions
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hard What is Event Sourcing? How does it differ from traditional CRUD? What are its advantages and drawbacks?
What interviewers evaluate: Data Consistency & Transactions
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hard How do you maintain data consistency across services that each own their own database?
What interviewers evaluate: Data Consistency & Transactions
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medium What is eventual consistency? How do you explain it to a PM who wants strong consistency everywhere?
What interviewers evaluate: Data Consistency & Transactions
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Resilience & Fault Tolerance (5)
Cover circuit breakers, bulkheads, retries with backoff, idempotency, and the patterns that prevent cascading failures in distributed systems.
medium What is the Circuit Breaker pattern? How does it prevent cascade failures?
What interviewers evaluate: Resilience & Fault Tolerance
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hard What is the Bulkhead pattern? How does it isolate failures?
What interviewers evaluate: Resilience & Fault Tolerance
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medium How do you implement retry logic with exponential backoff? What pitfalls should you avoid?
What interviewers evaluate: Resilience & Fault Tolerance
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medium How do you handle idempotency in microservices? Why is it important for retries?
What interviewers evaluate: Resilience & Fault Tolerance
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medium A user request fails across three services. How do you trace and debug the failure? (distributed tracing)
What interviewers evaluate: Resilience & Fault Tolerance
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Deployment & Operations (5)
Cover blue-green deployment, canary releases, Kubernetes, schema migrations, API versioning, and the operational concerns of running services in production.
medium What is blue-green deployment? How does it compare to canary deployment and rolling updates?
What interviewers evaluate: Deployment & Operations
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medium How does container orchestration (Kubernetes) help with microservices deployment and scaling?
What interviewers evaluate: Deployment & Operations
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hard How do you handle database schema migrations in a microservices architecture?
What interviewers evaluate: Deployment & Operations
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medium How do you manage API versioning across dozens of microservices?
What interviewers evaluate: Deployment & Operations
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medium How do you implement centralized logging and monitoring across distributed microservices?
What interviewers evaluate: Deployment & Operations
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Database Design (12)
Compare SQL vs NoSQL, sharding strategies, replication, the CAP theorem, indexing, and the database design decisions that determine system performance.
medium When would you choose SQL vs NoSQL? Walk through a decision framework.
What interviewers evaluate: Database Design
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hard Explain database sharding strategies. How do you choose a shard key?
What interviewers evaluate: Database Design
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medium What is database replication? Compare master-slave vs master-master replication.
What interviewers evaluate: Database Design
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medium Explain normalization vs denormalization. When would you deliberately denormalize?
What interviewers evaluate: Database Design
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hard What is database federation (functional partitioning)? What are its tradeoffs?
What interviewers evaluate: Database Design
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medium What is the CAP theorem? Give a real-world example of choosing CP vs AP.
What interviewers evaluate: Database Design
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hard What is the PACELC theorem and how does it extend CAP?
What interviewers evaluate: Database Design
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medium Compare key-value, document, wide-column, and graph databases. Give use cases for each.
What interviewers evaluate: Database Design
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medium How would you design a database schema for a ride-sharing application?
What interviewers evaluate: Database Design
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medium What is consistent hashing? How does it help with data distribution?
What interviewers evaluate: Database Design
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medium What are database indexes? When would adding an index hurt performance?
What interviewers evaluate: Database Design
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medium Explain ACID vs BASE consistency models with examples.
What interviewers evaluate: Database Design
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API Design (8)
Cover REST, GraphQL, gRPC, pagination, idempotency, versioning, and the API design patterns that make services usable, scalable, and maintainable.
medium Compare REST, GraphQL, and gRPC. When would you choose each?
What interviewers evaluate: API Design
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medium Design a RESTful API for an event ticketing system. Define resources, endpoints, and response formats.
What interviewers evaluate: API Design
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medium How do you handle API pagination? Compare offset, cursor, and keyset pagination.
What interviewers evaluate: API Design
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medium What is API idempotency? How do you implement it for payment endpoints?
What interviewers evaluate: API Design
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medium How do you version an API? Compare URL versioning, header versioning, and query parameter versioning.
What interviewers evaluate: API Design
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medium What is an API Gateway? How does it differ from a load balancer and a reverse proxy?
What interviewers evaluate: API Design
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medium How do you design APIs for real-time communication? Compare long polling, WebSockets, and Server-Sent Events.
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medium What is the BFF (Backend For Frontend) pattern? When is it useful?
What interviewers evaluate: API Design
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Real-World System Breakdown (6)
Analyze how Netflix transcodes video, how Uber matches drivers, how Google indexes the web, and how WhatsApp scales end-to-end encryption.
hard How does Netflix handle video transcoding and adaptive bitrate streaming at scale?
What interviewers evaluate: Real-World System Breakdown
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hard How does Uber match riders with drivers in real-time? Discuss the architecture.
What interviewers evaluate: Real-World System Breakdown
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hard How does Google Search index billions of web pages and return results in milliseconds?
What interviewers evaluate: Real-World System Breakdown
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hard How does WhatsApp achieve end-to-end encryption while supporting group chats?
What interviewers evaluate: Real-World System Breakdown
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hard How does Amazon handle inventory consistency during flash sales (millions of concurrent buyers)?
What interviewers evaluate: Real-World System Breakdown
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hard How does Slack maintain real-time messaging across thousands of channels and workspaces?
What interviewers evaluate: Real-World System Breakdown
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Google (6)
Design Google-style systems: YouTube, Maps, Photos, and the planet-scale services Google interviewers expect you to architect from scratch.
hard Design YouTube (video upload, storage, streaming, recommendations)
What interviewers evaluate: Google
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hard Design Google Maps (routing, real-time traffic, geospatial queries)
What interviewers evaluate: Google
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hard Design Google Photos (image storage, ML-based search, sharing)
What interviewers evaluate: Google
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medium Design an online booking system for a restaurant
What interviewers evaluate: Google
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hard Design cloud computing redundancy for compute clusters
What interviewers evaluate: Google
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medium Design a news front page with source aggregation
What interviewers evaluate: Google
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Meta (6)
Design Meta-style systems: Instagram Stories, live commenting, Facebook search, and the social platforms Meta engineers build at multi-billion-user scale.
hard Design Instagram Stories
What interviewers evaluate: Meta
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hard Design a live commenting system for posts
What interviewers evaluate: Meta
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hard Design Facebook status search
What interviewers evaluate: Meta
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hard Design a travel booking system for Facebook users
What interviewers evaluate: Meta
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hard Design a system preventing foreign actors from interfering in politics
What interviewers evaluate: Meta
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hard Design the API layer for Facebook chat
What interviewers evaluate: Meta
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Amazon (6)
Design Amazon-style systems: warehouse management, inventory, food delivery, and the logistics systems that power Amazon's retail and AWS businesses.
hard Design a warehouse management system
What interviewers evaluate: Amazon
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medium Design software for Amazon pickup locations with lockers
What interviewers evaluate: Amazon
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hard Design a food delivery app at global scale
What interviewers evaluate: Amazon
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medium Design an inventory management system
What interviewers evaluate: Amazon
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medium Design a promotion mechanism (10% cashback on credit card)
What interviewers evaluate: Amazon
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hard Design a system to optimally fill a truck for deliveries
What interviewers evaluate: Amazon
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OpenAI / Anthropic (6)
Design LLM infrastructure: enterprise search, conversational AI, batched inference, and the high-throughput systems that serve large language models.
hard Design an LLM-powered enterprise search system
What interviewers evaluate: OpenAI / Anthropic
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hard Design the Claude/ChatGPT chat service (multi-turn, streaming, context management)
What interviewers evaluate: OpenAI / Anthropic
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hard Design a batched inference system for LLMs
What interviewers evaluate: OpenAI / Anthropic
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hard Design a high-concurrency inference API with parallel processing pipeline
What interviewers evaluate: OpenAI / Anthropic
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hard Design APIs for developers accessing AI models (rate limiting, auth, usage tracking)
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hard Design a system enabling LLMs to handle multiple questions in threads
What interviewers evaluate: OpenAI / Anthropic
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NVIDIA (3)
Design GPU-related systems: job schedulers for GPU workloads, memory allocators, and the infrastructure that powers modern AI training and inference.
hard Design an interface for managing jobs on GPUs
What interviewers evaluate: NVIDIA
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hard Design a memory allocator for GPU workloads
What interviewers evaluate: NVIDIA
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medium Design a proximity server
What interviewers evaluate: NVIDIA
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