JavaScript engineering patterns
Build a cache, order dependent jobs, retain async outcomes and reason about sliding windows.
Prerequisite: JavaScript foundations · 115 minutes of guided study
4 focused engineering lessons with executable tests.
Open interactive course →Engineering practice
- Project · A bounded LRU cache35 min →
Keep recency and capacity as explicit invariants.
- Order jobs and detect dependency cycles30 min →
A topological order exists only for a directed acyclic graph.
- Preserve outcomes across asynchronous failures25 min →
Choose a failure policy before choosing a Promise combinator.
- Find the longest unique-character window25 min →
Maintain a moving invariant instead of rebuilding every substring.