TypeScript applications, migrations, and full-stack systems built by the team behind procedure.tech, Setu, KredX, and Last9.
Trusted by engineering teams at
Moving JavaScript codebases to TypeScript, incrementally. We start with strict: false, add types to critical paths first, then tighten the compiler until the codebase is fully strict. Your app stays live throughout. No productivity freeze, no big-bang rewrite. We have migrated codebases with 200K+ lines of JavaScript to strict TypeScript without a single day of downtime.
Large-scale TypeScript applications with NestJS, React 19, and Next.js 16. Monorepos with Turborepo, shared type packages, and strict compiler settings across every workspace. The type system becomes your documentation and your safety net. Runtime errors caught at build time, not by your users.
End-to-end type safety from database to UI. Prisma generates types from your schema, tRPC or GraphQL Codegen carries them through your API layer, and Zod validates runtime inputs at every boundary. A change to your database schema surfaces type errors in your React components instantly. No more silent contract mismatches between frontend and backend.
One language across your entire stack. React 19 or Next.js 16 on the frontend, NestJS or Fastify on the backend, Prisma or Drizzle for data access, all in TypeScript. Your team shares types, utilities, and domain logic across every layer. Fewer context switches, faster debugging, simpler hiring.
TypeScript libraries and SDKs with proper declaration files, generics, and discriminated unions. Published to npm with semantic versioning, automated changelogs, and dual ESM/CJS output. We build packages that feel native to TypeScript, not JavaScript wrappers with .d.ts files bolted on.
ESLint with typescript-eslint, Vitest for unit and integration tests, Playwright for end-to-end coverage. Strict compiler options enforced via CI. We configure tsconfig.json properly once so your team never debates compiler settings again. Every PR gets type-checked, linted, and tested before merge.
Every new TypeScript project starts with strict: true. No any types in production code. The compiler is your first line of defense against runtime errors, and we configure it to catch everything it can.
Well-designed TypeScript types communicate intent better than comments. When a function accepts a discriminated union instead of a string, the type system tells every developer what values are valid without reading a wiki page.
Types that stop at the API boundary are half the value. We use Prisma, tRPC, and Zod to carry type safety from the database through the API to the UI. A schema change surfaces errors everywhere it matters, instantly.
For migrations, we prioritize progress over perfection. Start with loose types on legacy code, strict types on new code, and tighten gradually. Your team ships features while the migration happens in the background.
We do not rely on code review to catch type issues. CI pipelines run the TypeScript compiler, ESLint with typescript-eslint, and test suites on every pull request. Standards are automated, not aspirational.
We assess your existing codebase, identify type coverage gaps, and define the migration or build strategy. You get a technical proposal covering compiler configuration, module boundaries, shared type packages, and CI/CD integration. For greenfield projects, we establish the TypeScript architecture before writing application code.
tsconfig.json configured for your project's needs. ESLint rules set. Shared type packages created if using a monorepo. For migrations, we establish the incremental adoption path and convert critical modules first. For new builds, the type system and toolchain are locked before feature development begins.
Sprint-based TypeScript development with strict type checking on every pull request. Your team sees working features shipped continuously. For migrations, we convert module by module while the application stays live. Type coverage tracked and reported weekly.
Full TypeScript strict mode enabled and verified. No any types in production code. Vitest and Playwright test suites passing. Bundle analysis completed to confirm TypeScript compilation produces optimized output. Performance benchmarks met.
Complete documentation covering TypeScript conventions, compiler configuration decisions, and type architecture. Your team owns the codebase and can extend it without us. Optional support retainer available, but no lock-in.
Engineers with 4+ years of production TypeScript experience across React, Node.js, and full-stack applications. Deep understanding of generics, conditional types, and compiler internals. Not developers who learned TypeScript last month.
A self-contained team that owns full feature delivery in TypeScript. Architecture, implementation, testing, and deployment covered. Mixed team of leads and senior engineers staffed based on project needs.
Fixed-scope engagement with clear deliverables, timeline, and budget. Defined type contracts, agreed milestones, and transparent pricing.
Talk directly with engineers, not sales. We will assess fit and give honest next steps.
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TypeScript development costs depend on project scope. A JavaScript-to-TypeScript migration for a medium codebase (50K-100K lines) typically runs $20,000 to $60,000. A full-stack TypeScript application with 15-25 screens costs $40,000 to $120,000. Enterprise platforms with monorepo architecture, shared type packages, and multiple teams can run $120,000 to $350,000+. Procedure offers a free architecture consultation to scope your specific project.