Learn system design by playing

A free puzzle game where you fix live systems with caches, queues and servers.

Play level 1 Levels

Free · Account optional · Works offline

COGOREPostgresRedisAPIUsers

How it plays

  1. 1Drag a part

    Drop a cache, a queue or a server onto a link.

  2. 2Watch it run

    Traffic flows at once. Busy parts glow hot and slow down.

  3. 3Hit the goals

    Meet the latency and cost goals. A cheaper design earns more stars.

The path

41 short levels in 8 chapters. Each chapter ends with a boss level.

  1. 01 One machine 7 levels
  2. 02 Caching 5 levels
  3. 03 Many machines 4 levels
  4. 04 Queues 5 levels
  5. 05 Failure 5 levels
  6. 06 Copies 6 levels
  7. 07 Partitions 5 levels
  8. 08 Planet scale 4 levels

The first system is already melting

Play level 1