System Design

⏱ 5 min read Core Entities Vehicle: vehicle_id, vin (unique), make, model, year, type (SEDAN, VAN, TRUCK, ELECTRIC), status (AVAILABLE, ASSIGNED, IN_MAINTENANCE, OUT_OF_SERVICE), current_driver_id, […] Read article

⏱ 6 min read What is a CDN and Why Does It Matter? A CDN is a geographically distributed network of edge servers that Read article

⏱ 5 min read Core Entities Problem: problem_id, title, slug, difficulty (EASY, MEDIUM, HARD), statement_markdown, constraints, time_limit_ms, memory_limit_mb, tags (array), is_active. TestCase: tc_id, problem_id, Read article

⏱ 5 min read Requirements A payment gateway processes card transactions between merchants and issuing banks. Core flow: customer enters card details → merchant Read article

⏱ 5 min read Core Entities Warehouse: warehouse_id, name, address, total_locations, is_active. Location: location_id, warehouse_id, zone (RECEIVING, STORAGE, STAGING, SHIPPING), aisle, bay, level, bin, Read article

⏱ 5 min read Requirements A location service has two core functions: proximity search (find entities near a given coordinate — restaurants, drivers, friends) Read article

⏱ 5 min read Core Entities Cinema: cinema_id, name, address, timezone. Hall: hall_id, cinema_id, name, total_rows, total_cols, layout_type (STANDARD, IMAX, VIP). Seat: seat_id, hall_id, Read article

⏱ 5 min read Requirements A gaming backend handles player authentication, matchmaking (pairing players of similar skill), real-time game state synchronization, leaderboards, and player Read article

⏱ 5 min read Why Multi-Region? A single-region architecture has three critical weaknesses: latency (a user in Tokyo hitting servers in us-east-1 has ~150ms Read article

⏱ 5 min read Core Entities Product: product_id, sku (unique stock keeping unit), name, description, category_id, unit_cost, unit_price, weight_kg, dimensions_cm (JSON), is_active. Warehouse: warehouse_id, Read article

⏱ 5 min read Core Entities Driver: driver_id, user_id, vehicle_id, license_number, status (OFFLINE, AVAILABLE, ON_TRIP), current_lat, current_lng, last_location_update, rating, total_trips, acceptance_rate. Vehicle: vehicle_id, driver_id, Read article

⏱ 5 min read Requirements A media storage and delivery system stores uploaded videos or images and delivers them efficiently to users worldwide. Think Read article

⏱ 7 min read Requirements A typeahead service returns query suggestions as the user types. Google Search autocomplete, Twitter’s hashtag completion, and Stripe’s dashboard Read article

⏱ 8 min read Core Entities Hotel: hotel_id, name, address, star_rating, amenities (JSON array), check_in_time, check_out_time. RoomType: type_id, hotel_id, name (STANDARD, DELUXE, SUITE, PENTHOUSE), Read article

⏱ 8 min read Core Entities User: user_id, username (unique, URL-safe), email, password_hash, display_name, bio, avatar_url, role (READER, AUTHOR, EDITOR, ADMIN), created_at. Post: post_id, Read article