Services
TypeScript Development Services
TypeScript catches a category of bugs before they reach production — wrong argument types, undefined properties, API responses that don't match what the frontend expects. I use it by default on every project, and I also take on migrations of existing JavaScript codebases that have grown past the point where untyped code is manageable.
The value isn't the type annotations themselves, it's what they enable: safer refactors, better autocomplete, and a contract between frontend and backend that the compiler enforces instead of relying on documentation staying accurate.
Problems This Solves
- arrow_rightRuntime errors from typos or wrong assumptions about a value's shape that only show up in production
- arrow_rightA JavaScript codebase that's become risky to refactor because nobody's sure what depends on what
- arrow_rightAPI responses drifting out of sync with what the frontend expects
- arrow_rightOnboarding new developers who have to read implementation code to understand what a function expects
What's Included
- checkIncremental JavaScript-to-TypeScript migration (file by file, no big-bang rewrite)
- checkShared types between API and frontend
- checkStrict mode configuration tuned to the project's risk tolerance
- checkType-safe form validation and API clients
- checkESLint rules that enforce type discipline going forward
How I Work
- Set up the TypeScript config and get the build passing with permissive settings first
- Migrate high-traffic or high-risk files first — the ones where a bug costs the most
- Tighten compiler strictness incrementally as coverage improves
- Add types to API boundaries so frontend and backend can't silently drift apart
- Document any intentional escape hatches (any, unknown casts) so they're easy to find later
Technology Stack
- arrow_rightTypeScript
- arrow_rightReact / Next.js
- arrow_rightNode.js
- arrow_rightZod or similar for runtime validation
- arrow_rightESLint with typescript-eslint
Suitable For
Teams running a JavaScript codebase that's grown large enough that bugs from type mismatches are a recurring cost, and new projects that want type safety built in from the first commit rather than retrofitted later.
Frequently Asked Questions
Does migrating to TypeScript mean rewriting the app?add
No. TypeScript is a superset of JavaScript, so files can be converted one at a time (.js to .ts) while the rest of the app keeps running. I typically start with the highest-risk or most-changed files rather than doing it all at once.
How long does a migration take?add
It depends entirely on codebase size and how dynamic the existing JavaScript is. A focused migration of the core data layer and API boundary is usually the highest-value first step, and can happen incrementally alongside regular feature work rather than as a separate blocking project.
Is strict mode worth turning on?add
For new projects, yes, from day one — it's much harder to retrofit strict null checks onto a large existing codebase. For migrations, I usually start loose and tighten settings gradually as coverage improves.
Do you use TypeScript on the backend too?add
Yes, when the backend is Node.js — it lets types flow from the database layer through the API to the frontend with a single source of truth for shared types.