A guide to hiring TypeScript developers
TypeScript is JavaScript with types. A developer writes code in TypeScript, and a compiler checks it and turns it into plain JavaScript that runs in the browser or on a server. The types describe what each piece of data looks like, so the editor and the compiler can warn about mistakes early. A TypeScript developer is a software developer who uses this well on real products. This guide explains what the role covers, how it differs from a JavaScript developer and how to set up the work so your codebase gets clearer instead of more complicated. It suits a team starting a new product as well as a company with an older JavaScript project that has grown hard to change.
What TypeScript developers work on
The work covers the same ground as other web development: screens, APIs, data and tooling. What changes is how the code is written. A TypeScript developer defines types for the data that moves through the app, such as users, orders or settings, and then lets the compiler check every place that data is used. On a back end they type requests and responses. On a front end they type component inputs and API calls. Many projects also share types between the two, so the browser and the server cannot quietly drift apart.
Freelance or dedicated
Many people search for a freelance TypeScript developer. A freelancer can be a fair choice for a small, clear job, such as typing one module or fixing one build problem. TypeScript work often needs more than that. Good types depend on knowing the whole codebase, and that knowledge builds over months. DigiWorks is not a freelance marketplace. We place dedicated remote developers who work in your tools and stay with your product. We find and vet the candidates, you interview them and you decide who starts.
How this role differs from a JavaScript developer
Almost every TypeScript developer is also a JavaScript developer, because TypeScript builds on it. A JavaScript developer is the right pick for browser scripts, small sites and interactive features, where plain code is enough. A TypeScript developer adds the skills of designing types, using strict settings and moving projects over safely. Related roles include a Node.js developer for back ends, a React developer for screens, an Angular developer, since Angular is written in TypeScript, and a full stack developer for both sides. Use this page when typed code is the main need.
When TypeScript is a good fit
- Your product is large or will be worked on for years.
- Several developers change the same code, and mistakes slip through review.
- Your front end and back end share data, and the two sides drift apart.
- Your JavaScript project has become hard to change without breaking something.
- You build a package or API that other teams will use.
When plain JavaScript may be enough
Types add some setup and some learning. For a short script, a simple marketing site or a quick prototype, the extra work may not pay back. A good developer will say so. Ask candidates when they would not use TypeScript. Someone who can answer that has thought about the cost as well as the benefit.
What to decide before you hire
- Whether you are starting fresh or moving an existing JavaScript project.
- Which framework and runtime you use on the front end and the back end.
- How strict you want the compiler to be, and how fast you want to get there.
- Who reviews the code and how types are agreed on in the team.
- Whether the developer will work alone or with others on the same repository.
Reading a TypeScript developer’s portfolio
Ask to see code, not only finished products. Look at a repository or a pull request. Check whether types describe the real data, whether the code leans on loose types to get past errors, and whether names and interfaces read well. A short note on how the person moved a project to TypeScript, and what it caught, tells you more than a list of tools. Be careful with a portfolio that shows only small demos, because the hard part of TypeScript appears in large codebases.
Interview questions to try
- When do you use an interface and when a type alias, and how do you decide?
- What is wrong with using a loose type to silence an error, and what do you do instead?
- How would you move a large JavaScript project to TypeScript without stopping releases?
- Types disappear when the code runs. How do you check data that comes from outside?
- Tell us about a bug that TypeScript caught, and one it did not.
Listen for specific examples and honest trade-offs. Doubt anyone who says types remove the need for tests.
Run a small paid task
Give each finalist a short brief from your own code. Good tasks include adding types to one module, reviewing a pull request and listing the risks, or building a small typed endpoint with tests. The time should be paid. Read the result for clear names, careful types and a short note on the choices made. Give every finalist the same brief so you can compare fairly.
Give them tools and a rhythm
Your developer needs the code repository, the build pipeline and the project board, but nothing beyond that. The repository and accounts should be registered to you. Agree early on the compiler settings, the lint rules and how pull requests are reviewed, and write them down. A short written update each week and a demo every other week is enough, as long as the update follows the same shape each time.
Plan the first months
In the first weeks, the developer reads the code, runs the project and ships one small change. Then they take on a slice of the work, such as one feature or one package. For a migration, agree on the order of folders, the strictness goals and a way to measure progress that the whole team can see. By the third month, a good developer plans work with you and points out the parts of the code that need care.
Mistakes to avoid
- Turning on TypeScript but leaving the compiler settings so loose that little is checked.
- Filling the code with loose types to make errors go away.
- Trusting types for data that comes from users or outside services without checking it.
- Trying to rewrite the whole project at once instead of moving in steps.
- Handing the repository or hosting account to a contractor instead of keeping it in your name.
Need people for the wider team? Read about how to hire a software engineer or a web developer, and see how hiring works on our pages.