Hire TypeScript Developers: Rates, Vetting and What It Costs

Types that compile and tell you nothing

A client came to us with a Next.js and Node codebase built over eight months by a contractor who interviewed well. The app worked. Then they asked for a change to how orders were priced, and the change touched forty files. We opened the repo and found the reason: strict was false in tsconfig, there were 340 uses of any, and every API boundary was typed by hand with an interface that had drifted from what the server actually returned. The types were decoration. They compiled. They told you nothing true.

That is the whole job, and it is why people misjudge the hire. TypeScript is not JavaScript with annotations bolted on. A real TypeScript developer designs the type system as the cheapest test suite you will ever own. They make illegal states unrepresentable, so an order cannot be both status: "refunded" and carry an unpaid balance, because a discriminated union will not let it. They put a runtime validator at every edge where data enters the process, usually Zod or Valibot, and derive the static type from that schema so the compiler and the runtime cannot disagree. They generate types from the source of truth instead of retyping it, whether that is Prisma or Drizzle for the database, openapi-typescript for a REST contract, or GraphQL Code Generator for a schema.

Where hiring goes wrong: you interview someone who has written TypeScript for four years and has never once written a generic constraint, never used a discriminated union, and reaches for as the moment the compiler pushes back. They ship fast for two months. They are effectively writing JavaScript in a file with a .ts extension, and the compiler is silently agreeing with every lie. The bill arrives later, when a refactor that should take an afternoon becomes a two-week archaeology project because nothing in the codebase can be trusted to be what it claims.

Four ways to buy TypeScript work

In-house hire. Right when TypeScript is your permanent stack and the codebase will live five years. You get someone who accumulates context, owns tsconfig decisions, and cares about the type architecture because they have to live in it. The cost is time and risk: a bad in-house TypeScript hire is expensive to remove and their type debt outlives them. Fits funded companies with an existing engineer who can vet the hire.

Freelancer. Right for a bounded piece of work with a clear edge: migrate a JavaScript service to strict TypeScript, build one feature, add end-to-end type safety to an API layer. Cheap and fast when scoped tightly. The trade is that freelancers optimize for shipping the ticket, and type architecture is exactly the thing that gets sacrificed when someone is judged on velocity alone. If nobody reviews their pull requests with an eye on the types, you will inherit any and casts.

Agency. You buy a team plus the review layer plus continuity when someone leaves. Costs the most per hour and you accept less direct control over who touches the code day to day. Fits founders and ops leaders without an engineering counterpart in the building, where the risk of nobody catching bad decisions is higher than the premium.

Staff augmentation. One or two developers who join your standups, your repo, your process, and follow your lead. Cheaper than an agency, more accountable than a freelancer, no permanent headcount. Fits teams that have an engineering lead but not enough hands. This is the most common shape we deliver, and it works because the lead is still setting type conventions and the augmented developer follows them.

Rates and what it really costs

These are Digital Heroes delivery ranges and what we see in the market when we bid against others. Rates move with region, seniority, and how much domain modeling the role carries.

Offshore, meaning India, Pakistan, the Philippines and similar markets: roughly $25 to $60 per hour. The floor of that band buys you someone who writes JavaScript with types. The upper half buys real generic and inference skill, and it exists there, but you have to vet for it rather than assume it. Eastern Europe and Latin America: roughly $60 to $110 per hour, with heavy overlap with US working hours from LatAm. Onshore US, UK, Western Europe: roughly $110 to $200 per hour, higher if the role includes architecture ownership across a monorepo.

For a full-time in-house hire, the salary is not the cost. Benefits, payroll taxes, equipment, software and workspace push the base up meaningfully, and in our own budgeting we plan on total cost sitting noticeably above the number on the offer letter rather than equal to it. Then add recruiting: either a fee if you use an agency, or weeks of your own engineers' time doing screens and reviewing take-homes, which is real money you do not see on an invoice. Then add ramp. A senior TypeScript developer joining an existing codebase is meaningfully productive in a few weeks and fully productive in one to three months, depending on how bad the type situation already is. If you need output in three weeks, an in-house hire will not give it to you at any salary.

How to vet a TypeScript developer

Screen the work, not the resume. Ask for a repository and open the tsconfig first. If strict is false in a greenfield project they controlled, ask why. The answer tells you everything: a good developer will explain that they inherited it and were migrating incrementally with strictNullChecks first, or that they turned it on day one. A weak one will say strict mode is annoying.

Then grep the repo for any and as. Every codebase has a few. Ask them to walk you through three specific ones. A good developer defends them precisely, for example a cast at a boundary immediately after a Zod parse, or an any in a generic constraint where the alternative was worse, and they can name what they gave up. A weak one cannot remember writing it.

Questions that separate people fast:

• Walk me through the last discriminated union you designed and what bug it prevented. If they have never designed one, they have never modeled a domain in TypeScript.
• How do you type data crossing the network boundary? The answer you want mentions runtime validation with Zod, Valibot or io-ts, and deriving the static type from the schema with z.infer. The answer that fails: "I write an interface that matches the API docs."
• When would you use unknown instead of any? Basic, but it filters a shocking number of candidates.
• Explain a time you used a conditional type or a mapped type and whether it was worth it. You are testing judgment as much as knowledge. Someone who has never reached for them may be fine. Someone who reaches for them constantly is building a puzzle your team will have to solve at 2am.
• What is your tsconfig for a new Node service? Listen for strict, noUncheckedIndexedAccess, exactOptionalPropertyTypes, and a real position on module resolution.

A good take-home for this stack is small and boundary-heavy. Give them a JSON payload with one optional field, one field that is a union of three shapes, and one field that lies about its type in one case. Ask them to build a typed client for it and a function that handles all cases. Two hours, maximum. What you are grading: did they validate at runtime or trust the shape, did they model the union as a discriminated union or as an interface with everything optional, and does the compiler catch it when you add a fourth variant to the union. The last one is the real test. Add the variant yourself after they submit and see if tsc screams. If it stays silent, their types were decoration.

Red flags

They use as to fix type errors. A cast is you telling the compiler you know better. Sometimes true, usually not. Better question: "Show me a cast in your code and tell me what you verified before writing it."

Their interfaces mirror the API docs by hand. This guarantees drift the day the backend changes and nobody tells the frontend. Better question: "How does your frontend find out when a backend response shape changes?" Good answers name generated types from OpenAPI or GraphQL, a shared package in a monorepo, or tRPC where both ends share the same source.

They cannot explain the difference between a type error and a runtime error. People who believe TypeScript protects them at runtime skip validation entirely and ship apps that explode on the first malformed response. Better question: "Your typed API client says name: string and the server sends null. What happens?"

Type gymnastics for their own sake. Four-level conditional types and recursive template literals in application code where a plain union would do. It reads as senior in an interview and is a maintenance liability in your repo. Better question: "When have you deliberately chosen a simpler type that was less precise?"

No opinion on the build and tooling. Someone who cannot discuss ts-node versus tsx versus tsc for a Node service, or what skipLibCheck does, or why a monorepo needs project references, has not run TypeScript in production. Better question: "Your typecheck takes four minutes in CI. What do you look at first?"

When to hire this role, and how we staff it

Hire a TypeScript specialist when the type system is the problem: a JavaScript codebase you need migrated safely, an API contract that keeps breaking between frontend and backend, a monorepo where builds and types have become the bottleneck, or a domain complicated enough that modeling it correctly is most of the work. Those are real jobs and a generalist will not do them well.

Do not hire one when what you actually need is a React developer, a Node backend developer, or a full-stack developer who happens to write TypeScript, which is most of them now. TypeScript is the language, not the job. If your problem is "our checkout is slow" or "we need a dashboard," hire for that problem and require TypeScript competence as a filter, not as the headline. And if you are on a monthly ship cycle with two engineers and no complex domain, you probably do not need someone who can write a conditional type at all. You need someone who turns on strict mode and does not lie in their interfaces.

At Digital Heroes we staff TypeScript work with the type architecture reviewed by a lead, regardless of who writes the code. The developer on your standup may be mid-level and priced accordingly. The tsconfig, the domain models, the boundary validation, and the generated-types setup get looked at by someone senior before they harden. That is deliberate: the expensive mistakes in this stack are not bugs, they are decisions made in week one that nobody notices until month nine. We scope engagements starting from what your codebase actually looks like, not from a rate card, and we would rather tell you that you need a React developer than sell you a TypeScript specialist you do not need.