Build Your Own

Don't just use the machinery — build it. Each track constructs a real piece of infrastructure stage by stage, with your code running against a test harness right in the browser.

Build Your Own Database

4 stages · 105 min · javascript · python

Build an LSM-tree storage engine -- the same architecture inside RocksDB, Cassandra, and LevelDB -- stage by stage, in your browser.

Build Your Own HTTP Server

4 stages · 95 min · javascript · python

HTTP is just text over a socket -- until you have to parse it yourself. Build the core of a real HTTP/1.1 server in four stages and stop treating load balancers and gateways as magic boxes.

Build Your Own Rate Limiter

3 stages · 70 min · javascript · python

Every public API in production has a rate limiter. Build three algorithms -- token bucket, fixed window, sliding window -- in Python, understand the trade-offs, and know exactly what Stripe's 429 means.

Build Your Own LRU Cache

3 stages · 75 min · javascript · python

Build the data structure that powers Redis's eviction policy, browser caches, and CDN edge nodes -- from scratch, in both JavaScript and Python.

Build Your Own Consistent Hash Ring

3 stages · 75 min · javascript · python

Build the data structure that DynamoDB, Cassandra, and Discord use to distribute data across nodes without remapping every key when the cluster grows or shrinks -- a hash ring with virtual nodes, O(log N) lookup, and a mathematical guarantee that only 1/N keys migrate on any topology change.