Learning advanced TypeScript: safer code step by step

This is a practical, hands-on workshop. We start from a tiny, messy codebase and improve it step by step. We’ll replace `any` with real boundaries, use `unknown` + simple type guards, model flows with discriminated unions, add domain safety with branded types, design ergonomic generics and validate inputs at runtime. Each step is a small refactor you can copy into your projects. Expect live coding, short exercises and practical patterns that reduce bugs without over-engineering.