TypeScript
Development.

●Expertise Level

TypeScript developer since version 2.0 (2016), witnessed the evolution from optional typing to strict mode becoming standard. Expert in advanced type system features: conditional types, mapped types, template literal types, and type inference. Built type-safe codebases with 500K+ lines and zero 'any' types in strict mode.

Claude Pilot's codebase demonstrates TypeScript's power for developer tools. The Electron app shares types between main process, renderer, and tRPC backend... changing a database schema updates types across the entire stack instantly. I implemented branded types for different ID types: type UserId = string & { __brand: 'UserId' }. This catches bugs at compile time where you'd accidentally pass a SessionId to a function expecting a UserId. The tRPC procedures use Zod schemas that TypeScript infers types from: const input = z.object({ sessionId: SessionId }), and the return type is inferred from the procedure implementation. For the memory browser, I used discriminated unions to model different database connections: type Connection = PostgresConnection | MemgraphConnection | QdrantConnection, with each having specific properties. TypeScript narrows the type after checking connection.type, providing autocomplete for database-specific methods. The result: 80% test coverage but honestly the type system catches more bugs than tests do... refactoring is fearless because the compiler validates everything.