TypeScript: Static Typing for the Entire JavaScript Ecosystem
TypeScript is the language Microsoft ships, Google uses at scale, and most modern React, Node.js, and Next.js projects adopt by default. It compiles to plain JavaScript while adding a static type system that catches whole classes of bugs before runtime — mismatched API responses, null access on optional fields, wrong function signatures, and more. This track covers TypeScript from first types through compiler internals, across 106 courses that span every level from A1 to C2.
What You Will Learn
You will start with string, number, boolean, unknown, and never, then build up through interfaces, type aliases, union and intersection types, generics, and utility types like Partial, Pick, Omit, and Record. Intermediate topics include type narrowing and type guards, discriminated unions, mapped types, template literal types, decorators, and runtime validation with Zod. You will apply TypeScript to real stacks — React props and hooks, Express APIs, Node.js, Next.js, GraphQL, tRPC, and type-safe ORMs. Advanced courses cover conditional types, the infer keyword, recursive and self-referential types, branded/nominal types, variadic tuples, authoring declaration files, and end-to-end type safety across monorepos with project references.
The Learning Path
The 106 courses run from A1 through C2 in a continuous progression. A1 and A2 courses establish the fundamentals: basic types, functions, arrays, tuples, enums, readonly, optional chaining, and nullish coalescing. B1 introduces classes, modules, strict mode, tsconfig best practices, generics, and working safely with DOM and Fetch APIs. B2 pushes into advanced generics with constraints and conditional types, decorators, testing with Jest, monorepo setup, and migration from JavaScript. C1 courses cover recursive types, the infer keyword and complex conditional types, writing custom utility types, type-level programming fundamentals, type-safe internationalization, and advanced React patterns. The track ends at C2 with TypeScript Compiler API internals, type-level arithmetic, higher-kinded type simulation, building type-safe parsers, constructing DSLs with TypeScript types, and Effect-TS.
How It Works
Each course is split into short, focused lessons you complete in the built-in code editor with real-time feedback. An AI tutor is available whenever you get stuck, and every concept is reinforced immediately with hands-on exercises rather than passive reading.