medium Problems
23 problems at medium level.
Design WhatsApp
System design interview solution for Design WhatsApp. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.
Design Spotify
Design Spotify with audio streaming, playlist management, recommendation engine, offline downloads, and a global audio CDN.
Design Instagram
Design Instagram with photo upload pipeline, fan-out news feed, stories, and explore page. Covers image processing, CDN delivery, and feed ranking.
Design a Job Scheduler
Design a distributed job scheduler supporting cron-like scheduling, task queues, failure retry with backoff, and priority-based execution.
Design Notification Service
System design interview solution for Design Notification Service. Includes requirements, API design, data model, architecture, scaling strategy, and.
Design Tinder
Design Tinder with geospatial matching, swipe queue generation, mutual like detection, and real-time chat. Covers GeoHash indexing and match algorithms.
Design Facebook
Design Facebook's social graph, news feed, friend suggestions, and notification system. Covers fan-out architecture, graph databases, and feed ranking.
Design Reddit
Design Reddit with subreddits, voting (hot/top/controversial algorithms), threaded comment trees, and karma.
Design Twitter
System design interview solution for Design Twitter. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.
Design YouTube: Video Upload, Transcoding, CDN and Recommendations
Solve the YouTube system design interview: video upload, transcoding pipeline, object storage, CDN streaming, view counts, recommendations, and scale.
Design Google Search
Design a web search engine with crawling, indexing, PageRank, query processing, and result ranking.
Design an E-commerce System
Design an e-commerce system for interviews: product catalog, search, cart, checkout, inventory reservations, payments, order workflow, scaling, and tradeoffs.
Design Netflix
System design interview solution for Design Netflix. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.
Design TikTok: Short Video Feed, Upload Pipeline and Recommendations
Solve the TikTok system design interview: video upload, transcoding, feed ranking, recommendations, CDN delivery, social graph, and scaling tradeoffs.
Design Shopify
Design Shopify as a multi-tenant SaaS e-commerce platform with storefront rendering, checkout, webhooks, and app ecosystem.
Design Airbnb
Design Airbnb with search (dates + location), booking system, pricing engine, and reviews.
Design a Message Queue
Design a distributed message queue with topics, partitions, consumer groups, ordering guarantees, and at-least-once delivery.
Design a Flight Booking System
Design a flight booking system with seat inventory, double-booking prevention, dynamic pricing, and GDS integration.
Design a Collaborative Code Editor
Design a collaborative code editor with real-time sync (CRDT/OT), code execution sandbox, syntax highlighting, and multi-cursor collaboration.
Design an Analytics Platform
Design an analytics platform with event ingestion, real-time aggregation, dashboards, and ad-hoc queries. Covers Lambda architecture and columnar storage.
Design Rate Limiter: Token Bucket, Sliding Window and Redis
Solve the rate limiter system design interview: token bucket, sliding window, Redis counters, distributed limits, API gateway placement, and tradeoffs.
Design a Digital Wallet
Design a digital wallet with balance management, P2P transfers, transaction history, and fraud detection.
Design a Payment System
Design a payment system for interviews: payment flow, idempotency keys, ledger data model, retries, reconciliation, fraud checks, scaling, and tradeoffs.