Learning Tracks

Core principles, each paired with live simulations you can break. The full curriculum, right here — pick any lesson.

System Design Fundamentals

4 lessons · 36 min

The core mental models behind every production system — capacity math, caching, sharding, and replication — each with a live simulation you can break.

1Back-of-Envelope Capacity Math8 min 2Caching: Hit Ratios Are Claims, Not Facts10 min 3Sharding: Splitting Data Without Splitting Yourself9 min 4Replication: Copies, Lag, and the Failover Window9 min