Devvista is a software development and growth agency that finds, places and manages dedicated TypeScript developers and migration engineers, serving clients in the US, UK, Australia, Canada and the UAE. Choose hourly hours, a small team, or a fixed price.
typescriptlang.org describes TypeScript as JavaScript with syntax for types, a strongly typed language that builds on JavaScript. Below: what our TypeScript developers do, when typing pays off, what a hire costs and how to check a candidate.
What our TypeScript developers build
Typed web applications
Front ends and full-stack apps where the types catch wrong data shapes while the code is written, not after a customer reports a bug.
APIs and back ends
Server code in TypeScript, so the data that leaves the API and the data the screens expect are checked against the same definitions.
JavaScript to TypeScript migrations
Moving a working JavaScript codebase to TypeScript module by module, with the app running throughout and tests guarding each step.
Shared types across front end and back end
One set of definitions used by both sides, so a change in an API shows up as an error in the screen that uses it.
Libraries and internal packages
Reusable code with clear types for several apps to share. See our hire Node.js developers page for server work.
TypeScript or plain JavaScript: when does the extra step pay off?
TypeScript adds a layer. It earns its place in some projects and not in others. The table gives our view.
| Project | Plain JavaScript | TypeScript |
|---|---|---|
| A small script or one-page widget | Fine, with little to gain from types | Often more setup than it is worth |
| An app several people will change for years | Mistakes in data shapes surface at run time | Types catch many of them while coding (typescriptlang.org describes better tooling at any scale) |
| An API consumed by several front ends | Contracts live in documents and memory | Contracts live in shared types the compiler checks |
| Our view | Keep it for small, short-lived code | Use it for anything that must be maintained |
Our hire React developers and hire Angular developers pages cover frameworks that are commonly written in TypeScript, and our guide to hiring dedicated developers covers the hiring models.
What it costs and how you can hire
You can buy TypeScript developers by the hour, from $10 to $100 depending on level, or as a fixed-price project from $500 to $100,000. Everything is priced in US dollars.
| Model | Best for | Pricing |
|---|---|---|
| Dedicated TypeScript developer by the hour | Keeping a typed codebase healthy and moving forward each month | By developer level |
| Small TypeScript team | A product that needs a typed front end and a typed API built together | Hourly, per person |
| Fixed-price build | A migration or a build with a written module list | By complexity |
| Scoping first | You have a JavaScript codebase and need a risk-ranked plan before changing it | A short engagement that ends in a written spec |
Illustration (an estimate, not a quote): migrating a 60-module JavaScript web app to TypeScript while it stays in use, at an assumed $40 an hour:
| Work | Hours |
|---|---|
| Audit and migration plan | 20 |
| Build and tooling set-up | 16 |
| Shared types and API definitions | 40 |
| Module-by-module conversion | 96 |
| Fixing the errors the types reveal | 44 |
| Test coverage on critical flows | 36 |
| Team handover and guidelines | 12 |
| Total | 264 hours, about $10,560 at $40 an hour |
A smaller codebase falls well below that, and one with little test coverage rises above it. Send an outline of your modules and we will price your own.
Which TypeScript developer profile you need
TypeScript work is either building new typed code or converting old code, and the two need different habits.
| Profile | What they do | Ask to see |
|---|---|---|
| TypeScript application developer | Builds new typed screens and services | A typed app and its type definitions |
| Migration engineer | Converts JavaScript to TypeScript safely in steps | A migration they completed and how they tested it |
| Type-system specialist | Designs shared types and strict settings for a team | A shared types package |
| Tooling engineer | Sets up build, linting and checks in the pipeline | A pipeline that fails on type errors |
Common situations and what to hire
TypeScript work is either new code or a conversion, and the arrangements differ.
| Your situation | What to hire | Why |
|---|---|---|
| A new product that should be typed from day one | A TypeScript developer or small team by the hour | Strict settings are cheapest when set at the start |
| A working JavaScript app you want to convert | A migration engineer on a fixed-price plan | Module-by-module steps keep the app running and reviewable |
| A front end and an API that keep disagreeing | A type-system specialist for a short engagement | Shared types turn a disagreement into a compile error |
What the first month of a TypeScript hire looks like
- Week one: repository access, the current build set-up and a written list of modules ranked by risk.
- Week two: strict settings and shared types agreed, with the first small module converted and tested.
- Week three: the next batch of modules converted, with the errors the types reveal fixed.
- Week four: pipeline checks that fail on type errors, a review of what remains, and a plan for the rest.
How to check any TypeScript developer before you hire
Put these to any candidate, from any company. Strong answers are concrete and admit what a choice costs.
- How strict will the compiler settings be, and why?
- How do you handle data that arrives from outside, such as API responses?
- How would you migrate this codebase without stopping the team?
- Where do you avoid the loose escape hatches in the type system, and where do you allow them?
- How are types shared between the front end and the back end?
- Which checks run in the pipeline before code is merged?
- Ask for a small paid trial task before you commit: a small typed module with a clear boundary, a test, and a note on how it handles unexpected data.
A confident timeline with no written scope behind it is a reason to keep looking.
Mistakes to avoid when hiring TypeScript developers
Teams adopt TypeScript and still get little from it for a few reasons.
- Turning checks off to make errors disappear, which keeps the old bugs.
- Converting everything at once, so no one can review the change.
- Typing the inside of the app but not the data that comes in from outside.
- Skipping the pipeline check, so type errors reach the main branch.
Hiring from the US, UK, Australia, Canada and the UAE
Devvista works remotely with clients in the US, UK, Australia, Canada and the UAE and has no office in any of them. Time zones and review dates are agreed up front, and work runs from written specs and video calls.
Who this is for, and who it is not
| A good fit | Not a fit |
|---|---|
| A business with a JavaScript product it must maintain and a wish for fewer runtime errors | A request for a rewrite of working code with no reason beyond fashion |
| A team adding a TypeScript specialist or a migration lead | A throwaway prototype where types add little |
| Owners who approve a risk-ranked plan and a staged migration | A project needing developers on site |