Design Patterns for Modern TypeScript
A pragmatic tour of design patterns for engineers who already know TypeScript. We skip the Gang of Four rote ceremony and focus on the patterns you actually reach for in modern TS, reactive UIs, and distributed systems. Each lesson names the classic pattern, its modern equivalent, and where the textbook version is overkill today.
5 lessons · ~1.5 hours
1. Patterns That Matter
Strategy & dependency injection
Strategy collapses to passing a function, and DI is just passing dependencies in as arguments.
Observer & reactivity
Observer is pub/sub, and it is the machinery underneath event emitters, signals, and reactive UIs.
Adapter & facade
Adapters reshape a messy external API, and a facade gives a simplified front over a subsystem.
Factory & builder
Factories centralize construction, and builders assemble configured objects step by step.
Distributed patterns: circuit breaker & idempotency
The resilience patterns GoF never covered but every staff review assumes — circuit breakers, retries, and idempotency keys.