Type Challenges
Around 190 puzzles solved purely in the type system, graded warm-up through extreme, each with an online judge and published community solutions. Working through them builds real fluency with conditional types, infer, recursion and template literal types.
More resources on TypeScript
TSConfig Reference
Option-by-option documentation of tsconfig.json from the TypeScript team: strictness flags, module resolution, emit, JSX, interop and project references, each with examples, defaults and the version that introduced it. Use it to configure a project deliberately rather than copying someone else's file.
Effective TypeScript: 83 Specific Ways to Improve Your TypeScript (2nd ed.)
The field's bible for the gap between 'my code compiles' and 'my types are good'. Eighty-three short items on TypeScript idioms and pitfalls, revised for TypeScript 5, covering structural typing, inference, type-level programming, declaration files and migrating JavaScript. Finish it and you can judge competing type designs and say why one is safer.
Total TypeScript: Essentials
The best single guided path from 'I know JavaScript' to 'I am confident in TypeScript'. Editor-first method: it teaches you to read tsc's error messages and use hover types as the feedback loop, which is the transferable skill. Matt Pocock's sixteen-chapter book, free to read in full online, taking a JavaScript developer through annotations, unions, narrowing, objects, classes, modules, generics and tsconfig setup. Finish it and you can type a React or Node codebase unaided.
The TypeScript Handbook
The official documentation written by the language team: everyday types, narrowing, functions, objects, generics, conditional and mapped types, modules and project configuration. After reading it you can annotate code and read compiler errors without guessing.