Tools, System Design & Engineering Pathways
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FAANG Real-World System Design Vault
55 BLUEPRINTSCurated from real interview debriefs at Google, Meta, Amazon, Uber, Stripe, and Netflix. Powered by SystemDesign.io canonical architectural patterns.
Design a URL Shortening service like TinyURL
Design a high-throughput, low-latency URL shortening service that generates compact 7-character aliases for long URLs with high read-to-write ratios and collision-free key generation.
Design Pastebin
Design a text and code-sharing pastebin service that stores large text payloads, generates unique access links, and automatically expires pastes.
Design Instagram
Design an image-sharing platform featuring asynchronous media processing, user follow graphs, and fan-out feed generation for millions of concurrent users.
Design Dropbox or Google Drive
Design a cloud file synchronization service that supports multi-device chunked uploads, delta sync, deduplication, and cross-client real-time synchronization.
Design Facebook Messenger or WhatsApp
Design a real-time messaging system supporting 1-on-1 chats, group conversations, read receipts, offline message queuing, and end-to-end encryption.
Design Twitter for millions of users
Architect a microblogging timeline engine handling sudden traffic spikes from breaking news, asynchronous tweet fan-outs, and rapid reverse-chronological timeline rendering.
Design Youtube or Netflix
Design a video streaming platform that supports multi-bitrate adaptive streaming (DASH/HLS), distributed CDN edge caching, and video ingestion transcode pipelines.
Design Typeahead Suggestion/Autocomplete
Build a real-time search autocomplete system that returns the top 5-10 query suggestions in under 30ms as the user types each keystroke.
Design an API Rate Limiter
Design a distributed, highly available rate limiter capable of enforcing tiered per-user and per-IP rate limits with atomic counters across distributed nodes.
Design a Distributed Metrics Logging and Aggregation System
Architect a multi-datacenter metrics pipeline (similar to Prometheus / Datadog) collecting billions of machine telemetry data points per second with downsampling and alerting.
Design a Distributed Stream Processing System like Kafka
Design an append-only distributed commit log system providing partitioned, ordered event streams with high throughput, consumer group rebalancing, and zero-copy OS transfers.
Design a Key-Value Store
Design a distributed key-value store (like DynamoDB or Cassandra) featuring tunable consistency (quorum), consistent hashing with virtual nodes, and SSTables/LSM trees.
Identify the K Most Shared Articles in Various Time Windows
Design a real-time analytics streaming engine that computes the top K most viral/shared articles across sliding time windows (past 5 minutes, 1 hour, 24 hours).
Design Web Crawler
Design a scalable distributed web crawler that traverses the World Wide Web, parses HTML content, filters duplicates with Bloom filters, and respects robots.txt politeness rules.
Design Facebook's News Feed
Architect Facebook's personalized News Feed engine combining real-time edge aggregation, ranking algorithms, and hybrid fan-out for billions of active users.
Design Yelp or Nearby Friends
Design a geospatial search engine capable of locating nearby places or friends within a radius using spatial indexing algorithms (QuadTrees, Geohash, Google S2).
System to Collect Performance Metrics from Thousands of Servers
Build a telemetry collection architecture aggregating system utilization metrics (CPU, disk, network, JVM) from 100,000+ nodes without overwhelming target networks.
Design Google Calendar
Design an enterprise calendar scheduling platform supporting recurring events, timezone transformations, meeting conflict detection, and real-time reminders.
Design a Distributed Queue like RabbitMQ
Architect a distributed message broker providing AMQP-style exchange routing, dead-letter queues, message deduplication, and consumer acknowledgments.
Design Google Analytics - User Analytics Dashboard and Pipeline
Design an enterprise analytics ingestion pipeline receiving client clickstream beacons, computing real-time conversions, and serving sub-second interactive OLAP queries.
Design a System for Sorting Large Data Sets
Design an external sorting system capable of ordering 100 Terabytes of data on machines with only 16 GB of RAM using multi-way external merge sort.
Top K Elements: App Store Rankings, Amazon Bestsellers, etc.
Design a real-time leaderboard service displaying the top 100 best-selling items or trending apps updated continuously across millions of purchases.
Design a Job Scheduler
Design a distributed cron-like task execution engine that schedules, distributes, and executes millions of jobs reliably at exact timestamps with retries.
Design a Notification Service at Scale
Design a centralized notification platform dispatching billions of push notifications, SMS, and emails across disparate device providers (APNs, FCM, Twilio, SendGrid).
Surge Pricing System: Uber - Stream Processing, etc.
Design Uber's dynamic surge pricing engine analyzing real-time supply (available drivers) and demand (app opens & ride requests) in geospatial hexagon cells (H3).
Netflix: Limit the Number of Screens Each User Can Watch
Design a distributed concurrency control service that enforces per-subscription active video playback limits (e.g., maximum 2 or 4 concurrent screens) with sub-second heartbeats.
Design an ETA Service and Location Sharing Between Driver and Rider
Design a real-time driver tracking and ETA calculation engine streaming GPS coordinates to riders with map matching and route graph traversal.
Design a Hotel Booking System: Room Availability, Reservation, Booking
Architect a hotel reservation platform that guarantees zero overbooking during concurrent checkout rushes through distributed locking, idempotent transactions, and 15-minute hold reservations.
Design an A/B Testing System (like Optimizely)
Design an enterprise experimentation platform supporting multi-layered A/B tests, deterministic bucket hashing, statistical significance calculations, and zero client latency degradation.
Design a Price Alert System for Amazon (or for Stock prices)
Design an alert system monitoring millions of stock prices or product items, matching incoming price tick streams against user price thresholds in under 1 second.
Design an IoC/Dependency Injection Framework
Architect a robust, compile-time or runtime Inversion of Control (IoC) container that resolves complex dependency graphs, circular dependencies, and component lifecycles.
Design a Credit Card Processing System
Design a PCI-DSS compliant credit card payment gateway that processes multi-currency transactions with strict idempotency, fraud detection, and zero double-charging.
Count Facebook Likes, Especially for High-Profile Users
Design a high-volume like counting service that prevents database write contention when a celebrity post receives tens of thousands of concurrent likes per second.
Design a Control Plane for a Distributed Database
Architect the control plane for a cloud database fleet orchestrating node provisioning, automated shard rebalancing, leader elections, and zero-downtime upgrades.
Design a User Login and Authentication System for a Website
Design a secure, distributed authentication service supporting OAuth 2.0 / OIDC, JWT access tokens, refresh token rotation, MFA, and distributed session revocation.
Develop a Weather Application
Design a global weather service ingesting satellite and radar feeds, caching localized forecasts by geohash, and serving hundreds of millions of mobile users.
Create a Document Management System like Wikipedia, Notion or Google Docs
Design a collaborative document workspace supporting block-based content editing, real-time collaboration with CRDTs, revision history, and full-text search.
Build a Marketplace Feature for Facebook
Design a local peer-to-peer buy/sell marketplace with geospatial item discovery, category hierarchies, buyer-seller chat, and fraud detection.
Design a System to Monitor the Health of a Cluster
Design an infrastructure health checker detecting machine failures, split-brain states, and zombie processes across 50,000 servers using gossip protocols and heartbeats.
Find a Rider for Uber or Uber Eats
Design the core ride-dispatch matching algorithm that pairs incoming ride/order requests with optimal nearby drivers based on ETA, ratings, and route optimization.
Design a Distributed Tracing System
Design an end-to-end distributed tracing platform (like Jaeger / Dapper / Zipkin) tracking request spans and causal DAG relationships across thousands of microservices.
Design Backend for an App to Distribute 6 Million Free Burgers in One Hour
Architect a flash promotion campaign engine capable of redeeming 6 million vouchers in 60 minutes (~1,666 redemptions/sec) under massive unauthenticated concurrency.
Design a File Downloader Library from Frontend to Backend
Design an enterprise-grade client-server file downloader SDK supporting concurrent byte-range downloads, pause/resume, integrity checksums, and adaptive chunk sizing.
Design a System to View Latest Stock Prices Worldwide
Design a real-time global financial ticker pushing live stock bid/ask quotes to millions of connected web and mobile devices with millisecond latency.
Develop a Photo Sharing Platform like Flickr or Google Photos
Design a personal photo cloud storage platform featuring asynchronous thumbnail generation, EXIF metadata extraction, search by album/tag, and automated deduplication.
Design an On-Call Escalation System
Design an enterprise incident alert escalation system (like PagerDuty) executing escalation policies, initiating multi-channel notifications, and tracking acknowledgments.
Design and Implement a Wire Transfer API
Design a high-security banking wire transfer API executing funds transfers between accounts with strict ACID guarantees, balance validation, and idempotency.
Design a Live Comments Feature for Facebook
Design a real-time live streaming comments engine delivering thousands of concurrent viewer comments to millions of viewers during live broadcasts with zero lag.
Design a Feature to Show the Number of Users Viewing a Page
Design Booking.com's live viewer counter ('14 people are currently looking at this hotel') using heartbeat beacons and approximate cardinality counters.
Design Facebook Likes Feature with Live Updates
Design the interactive Facebook reactions button providing instant local UI feedback, asynchronous aggregation, and live animated counter updates via WebSockets.
Create a System to Migrate Large Data to Google Cloud
Design an enterprise data migration pipeline moving 100 Petabytes of on-premises unstructured data to Google Cloud Storage with encryption, validation, and zero downtime.
Design a Distributed Botnet
Analyze the distributed architecture of command-and-control (C2) botnets (for cybersecurity defense and DDoS mitigation modeling) featuring P2P topologies and domain generation algorithms (DGA).
Create a Distributed File Transfer System like Bittorrent
Design a decentralized peer-to-peer file sharing protocol featuring torrent metadata parsing, distributed hash table (DHT) peer discovery, and rarest-first chunk exchange.
Design a Parts Compatibility Feature for an eCommerce Site
Design an automotive or PC parts compatibility engine (like PCPartPicker / Amazon Garage) matching complex compatibility constraints (socket types, wattage, dimensions).
Develop an Ads Management and Display System for a Social Feed
Design an ad-serving platform executing real-time bidding (RTB) auctions in under 50ms, budget pacing, user targeting, and conversion attribution.