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SDMastery

medium Problems

23 problems at medium level.

medium

Design WhatsApp

System design interview solution for Design WhatsApp. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.

9 min read
medium

Design Spotify

Design Spotify with audio streaming, playlist management, recommendation engine, offline downloads, and a global audio CDN.

9 min read
medium

Design Instagram

Design Instagram with photo upload pipeline, fan-out news feed, stories, and explore page. Covers image processing, CDN delivery, and feed ranking.

9 min read
medium

Design a Job Scheduler

Design a distributed job scheduler supporting cron-like scheduling, task queues, failure retry with backoff, and priority-based execution.

7 min read
medium

Design Notification Service

System design interview solution for Design Notification Service. Includes requirements, API design, data model, architecture, scaling strategy, and.

9 min read
medium

Design Tinder

Design Tinder with geospatial matching, swipe queue generation, mutual like detection, and real-time chat. Covers GeoHash indexing and match algorithms.

7 min read
medium

Design Facebook

Design Facebook's social graph, news feed, friend suggestions, and notification system. Covers fan-out architecture, graph databases, and feed ranking.

7 min read
medium

Design Reddit

Design Reddit with subreddits, voting (hot/top/controversial algorithms), threaded comment trees, and karma.

7 min read
medium

Design Twitter

System design interview solution for Design Twitter. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.

8 min read
medium

Design YouTube

Design YouTube with video upload/transcoding pipeline, adaptive streaming, view counting, recommendations, and a global video CDN.

9 min read
medium

Design Google Search

Design a web search engine with crawling, indexing, PageRank, query processing, and result ranking.

9 min read
medium

Design an E-Commerce Platform

Design an e-commerce platform with product catalog, shopping cart, inventory management, checkout, and order processing.

10 min read
medium

Design Netflix

System design interview solution for Design Netflix. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.

9 min read
medium

Design TikTok

Design TikTok with short video feed, recommendation algorithm, video upload/processing, and a global CDN.

7 min read
medium

Design Shopify

Design Shopify as a multi-tenant SaaS e-commerce platform with storefront rendering, checkout, webhooks, and app ecosystem.

7 min read
medium

Design Airbnb

Design Airbnb with search (dates + location), booking system, pricing engine, and reviews.

7 min read
medium

Design a Message Queue

Design a distributed message queue with topics, partitions, consumer groups, ordering guarantees, and at-least-once delivery.

7 min read
medium

Design a Flight Booking System

Design a flight booking system with seat inventory, double-booking prevention, dynamic pricing, and GDS integration.

8 min read
medium

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.

7 min read
medium

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.

7 min read
medium

Design Rate Limiter

System design interview solution for Design Rate Limiter. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.

9 min read
medium

Design a Digital Wallet

Design a digital wallet with balance management, P2P transfers, transaction history, and fraud detection.

7 min read
medium

Design Payment System

System design interview solution for Design Payment System. Includes requirements, API design, data model, architecture, scaling strategy, and tradeoffs.

9 min read