TypeScript at Scale in React Native: Strictness, Codegen, and Shared Packages

JavaScript’s dynamism accelerates prototyping but compounds defect density as teams grow. TypeScript adds static typing, enabling refactors with confidence—provided compiler settings are strict enough to prohibit implicit any creep through escape hatches.

Compiler flags and incremental builds

Enable strict, noImplicitAny, strictNullChecks, and noUncheckedIndexedAccess where feasible. Configure project references for large monorepos to preserve incremental compile performance in CI.

Codegen boundaries

Generate types from GraphQL schemas or OpenAPI specifications rather than hand-maintaining DTOs. For native modules, adopt codegen shipped with the New Architecture to align JavaScript and native method signatures.

Shared packages

Publish internal packages with explicit exports maps. Avoid circular dependencies that confuse bundlers and obscure initialization order across Metro and Node resolution.

Testing and linting

Pair TypeScript with ESLint type-aware rules and prettier for formatting consistency. Block merges on typecheck failures—treat them as build breakers.

Closing

Types are documentation that executes. Invest in education so contributors understand discriminated unions and generic constraints over clever casts.