TypeScript Developers for Building Maintainable Applications

When you hire TypeScript developers through Cortance, they come from our own network with 296 TypeScript projects in their histories as of October 2026. We match them on where they made types hold, because that is where most TypeScript work succeeds or fails.

Where does a TypeScript type stop protecting your code?

A TypeScript type is a promise that the compiler checks only inside your own code. Three places sit outside that check. Data that arrives at runtime is the first. An API response, a webhook payload or an App Store receipt can contain anything, and the type written for it stays a guess until code validates it. Escape hatches are the second. A migration under deadline collects any annotations and as casts, and each one moves an error from build time to a customer's screen. Code that nobody typed by hand is the third, and AI tools now write a growing share of it.

Cortance reads a TypeScript engineer's project history for those boundaries: validation where outside data enters, typed contracts with other teams and services, and type checks that run before a merge. A profile that only lists TypeScript next to a framework tells you much less.

Where a JavaScript-to-TypeScript migration should start

Nataliia N. led the front end of a restaurant platform where guests order from QR-code menus and pay online or split the bill. She moved the project to TypeScript, rebuilt its forms on React Hook Form and wrote its Stripe and Apple Pay flows, along with order, tax and discount logic. Pricing code is where a wrong type costs money, so a migration has to reach it early.

Oleh K. led JavaScript-to-TypeScript migrations on React and React Native apps for client projects and, by his account, cut runtime errors by about 40%. A measured result like that is worth asking any candidate about. A migration can also end with every file renamed to .ts and nothing checked.

When part of your codebase is still JavaScript, Cortance looks for this kind of history first: a migration the engineer led, with a result they can name.

Why do AI coding tools make type checks matter more?

TypeScript became the most used language on GitHub by monthly contributors in August 2025, and GitHub's Octoverse 2025 report ties that rise to developers working with AI agents. Typed code gives an agent a contract to write against. It also gives the reviewer a first check that runs in seconds, but only when the pipeline enforces it.

Oleh Sh. built CI pipelines for a generative AI assistant platform where type checks, lint, unit tests and Playwright end-to-end tests had to pass before any merge. A gate like that rejects a wrong type whether a person or an agent wrote the line. An agent that silences the error with any or a cast still gets through, and catching it takes an engineer who reads the diff. If your team already codes with agents, Cortance can shortlist from the 13 of 122 TypeScript engineers in our network who list Claude Code, Cursor or Copilot.

Tell us how far your types reach today

The state of your codebase decides the seniority you need. A half-converted project with strict mode off needs a senior engineer to plan the migration order and decide where validation goes. A fully typed codebase that only needs new features can take an engineer who works well inside rules someone else set. Our TypeScript pool leans senior, with 40 of the 50 profiles we reviewed at the senior level, with onboarding benchmarks of 2 days.