jsschools
System Design

2026 · advanced

System Design track

Learn to design large-scale systems through the runtime JS engineers actually ship on. Master the building blocks — load balancing, caching, sharding, replication, consistency, message queues, rate limiting — then apply them across 60+ real architecture case studies: URL shorteners, Twitter, YouTube, Gmail, WhatsApp, Uber, Google Docs and more. Every deep-dive is grounded in Node.js: WebSockets, streams, worker threads, Redis, and BullMQ.

Start the first lesson 44 of 105 lessons live
Categories: 🧠 Fundamentals 🛠️ Backend

Section 04

Communication & Messaging

Network protocols, API paradigms, realtime, WebSockets, message queues, and job queues in Node.

8 / 8 lessons
  1. 01 Network Protocols From HTTP/1.1 to HTTP/3 9 min
  2. 02 REST vs GraphQL vs gRPC 9 min
  3. 03 Real-Time Options for Pushing Data to Clients 8 min
  4. 04 WebSockets at Scale in Node 10 min
  5. 05 Message Queues and Brokers 10 min
  6. 06 Publish/Subscribe and Fan-Out 8 min
  7. 07 Background Jobs in Node With BullMQ 10 min
  8. 08 Idempotency and the Exactly-Once Myth 9 min

Section 05

Reliability, Scale & Operations

Rate limiting, API gateways, resilience, backpressure, observability, fault tolerance, and security.

11 / 11 lessons
  1. 01 Rate Limiting 9 min
  2. 02 API Gateway 8 min
  3. 03 Resilience Patterns 9 min
  4. 04 Backpressure & Node Streams 9 min
  5. 05 Observability 9 min
  6. 06 Fault Tolerance 8 min
  7. 07 Leader Election 9 min
  8. 08 Distributed Locks 9 min
  9. 09 Unique IDs at Scale 9 min
  10. 10 Search Systems 9 min
  11. 11 Authentication & Security 9 min

Section 06

Warm-ups — Classic Interview Systems

The foundational case studies — URL shortener, rate limiter, KV store, crawler, typeahead.

0 / 10 lessons
  1. 01 url shortener Soon
  2. 02 pastebin Soon
  3. 03 rate limiter system Soon
  4. 04 key value store Soon
  5. 05 unique id service Soon
  6. 06 web crawler Soon
  7. 07 typeahead Soon
  8. 08 notification system Soon
  9. 09 distributed cache Soon
  10. 10 leaderboard Soon

Section 07

Social & Feed

Twitter, Facebook News Feed, Instagram, Reddit, LinkedIn, TikTok, Pinterest, recommendations.

0 / 8 lessons
  1. 01 twitter Soon
  2. 02 facebook newsfeed Soon
  3. 03 instagram Soon
  4. 04 reddit Soon
  5. 05 linkedin Soon
  6. 06 tiktok feed Soon
  7. 07 pinterest Soon
  8. 08 recommendation system Soon

Section 08

Messaging & Realtime

WhatsApp, Slack, Discord, Messenger, Zoom, Google Docs, collaborative whiteboard.

0 / 7 lessons
  1. 01 whatsapp Soon
  2. 02 slack Soon
  3. 03 discord Soon
  4. 04 messenger Soon
  5. 05 zoom Soon
  6. 06 google docs Soon
  7. 07 collaborative whiteboard Soon

Section 09

Media & Streaming

YouTube, Netflix, Spotify, Twitch, image hosting, and the video transcoding pipeline.

0 / 6 lessons
  1. 01 youtube Soon
  2. 02 netflix Soon
  3. 03 spotify Soon
  4. 04 twitch Soon
  5. 05 image hosting Soon
  6. 06 video transcoding pipeline Soon

Section 10

Productivity & Storage

Gmail, Google Drive, Google Calendar, Notion, and multi-device file sync.

0 / 5 lessons
  1. 01 gmail Soon
  2. 02 google drive Soon
  3. 03 google calendar Soon
  4. 04 notion Soon
  5. 05 file sync Soon

Section 11

Commerce, Marketplaces & Geo

Amazon, payments, Ticketmaster, Uber, DoorDash, Airbnb, Maps, proximity, and inventory.

0 / 9 lessons
  1. 01 amazon ecommerce Soon
  2. 02 payment system Soon
  3. 03 ticketmaster Soon
  4. 04 uber Soon
  5. 05 doordash Soon
  6. 06 airbnb Soon
  7. 07 google maps Soon
  8. 08 nearby places Soon
  9. 09 inventory system Soon

Section 12

Search, Ads & Data-Intensive

Google Search, ad aggregation, A/B testing, analytics, schedulers, fraud, exchanges, and more.

0 / 16 lessons
  1. 01 google search Soon
  2. 02 ad click aggregator Soon
  3. 03 ab testing platform Soon
  4. 04 feature flags Soon
  5. 05 analytics pipeline Soon
  6. 06 log aggregation Soon
  7. 07 metrics monitoring Soon
  8. 08 distributed job scheduler Soon
  9. 09 fraud detection Soon
  10. 10 stock exchange Soon
  11. 11 online judge Soon
  12. 12 distributed counter Soon
  13. 13 flash sale Soon
  14. 14 news aggregator Soon
  15. 15 email newsletter Soon
  16. 16 iot ingestion Soon