Hire a freelance TypeScript developer

TypeScript is the language I use for everything: backends, frontends, tooling, and infrastructure code. Writing both sides of the stack in one language, with types flowing from the database to the UI, is the closest thing to a superpower a small team can have.

I have been writing TypeScript in production for most of the past decade, on codebases ranging from weekend size MVPs to platforms with over a million users.

Hunter Hartman CEO, VESYL

Absolutely tremendous developer, creator, and leader.

Ruan is exactly the person you want in the room. He is incredibly innovative and possesses a rare combination of elite technical capability and tremendous design skills.

He has my highest recommendation for any organization looking for a top-tier developer and leader.

What I can help with

  • Full stack TypeScript applications: Node.js backends and React frontends
  • End to end type safety with OpenAPI, tRPC style patterns, and shared types
  • Migrating JavaScript codebases to TypeScript incrementally
  • API design with runtime validation that matches the types
  • Monorepos and tooling with npm workspaces
  • Code review and architecture guidance for TypeScript teams

Experience

Every product I have shipped in recent years runs on TypeScript end to end: VESYL, Barry’s X, Queie, Flipfox, and my own projects. I have set up typed API clients generated from OpenAPI schemas, shared validation between server and client, and migrated aging JavaScript services without pausing delivery.

Questions

Can you migrate our JavaScript codebase to TypeScript?

Yes. I migrate codebases incrementally: set up the tooling, convert the riskiest modules first, and keep the build green the whole time. Your team keeps shipping features while the migration happens underneath.

Do you work across the whole stack or just one side?

The whole stack. Most engagements involve a Node.js backend and a React frontend, both in TypeScript, plus the deployment and infrastructure around them.

What does end to end type safety mean in practice?

It means the shape of your data is checked from the database to the browser. If an API response changes, the frontend fails to compile instead of breaking in production. I usually get there with OpenAPI generated clients or shared schema validation, depending on the project.

How do we get started?

Email [email protected] or book a quick chat at cal.com/ruanmartinelli/quick-chat. Tell me what you are building and where TypeScript fits, and I will follow up with a proposal.

Related guides

You can browse all guides or read more about working with me .

Let's chat

Send me an email and tell me what you are building and what kind of help you need.

If I am not the right fit, I will say so and try to point you to someone who is.

[email protected]
cal.com/ruanmartinelli/quick-chat