TypeScript development services
Not a framework. The safety net under every JavaScript project we ship.
Every JavaScript project we build is TypeScript: strict compiler settings, types shared between the browser and the server, and runtime validation with Zod at the boundaries where data actually arrives. We also migrate existing JavaScript codebases file by file, with the build green at every commit.
What is TypeScript, and what does it actually buy you?
TypeScript is JavaScript with a type checker. You describe the shape of your data and your function signatures, and the compiler tells you before deployment when something does not line up. The types are erased at build time, so what runs in the browser or on the server is ordinary JavaScript with no runtime cost attached.
The argument for it is maintenance, not elegance. In an untyped codebase, renaming a field on an API response means searching for a string and hoping. In a typed one, the compiler lists every place that breaks, including the three nobody remembered. That difference compounds. It is what makes a two-year-old project safe to change on a Friday, and it is why a new developer is useful in week one rather than month two.
Types are not validation, and treating them as such is the mistake we see most. Data from a form, an API or a JSON file is unknown at runtime, so we validate at the boundary with Zod and derive the TypeScript type from that one schema. Compile-time checking and a runtime guard from a single definition. The panel above is how this site refuses to build when a content file is malformed.
We write TypeScript everywhere: React and Next.js front-ends, Node and NestJS services, React Native apps, and the scripts that run in CI. Where a project is still plain JavaScript, we migrate incrementally, because we have never once seen a big-bang rewrite land on the date it promised.
How we use TypeScript
Strict configuration from day one
Strict mode, no implicit any, exhaustive switch checks, and lint rules that fail the build instead of warning into a log nobody opens.
Shared types across the stack
One definition of a customer or an order, used by the API, the web app and the mobile app, usually from a monorepo package.
Runtime validation at the boundaries
Zod schemas for forms, API responses, environment variables and content files, with the TypeScript type inferred from the schema.
JavaScript to TypeScript migration
File by file, starting with the modules that break most often, shipping the whole way through rather than freezing the roadmap.
Typed API clients
Clients generated from OpenAPI or GraphQL schemas, or end-to-end type safety with tRPC when both ends belong to us.
Codebase health
Removing any, replacing hand-written declarations with generated ones, and getting the type-check into CI where it can block a merge.
Our TypeScript toolchain
TypeScript compared with the alternatives
TypeScript vs plain JavaScript with JSDoc
JSDoc annotations get you most of the checking with no build step, which genuinely suits a small library. For an application with several developers, TypeScript's tooling, refactoring support and ecosystem types repay the compile step within a month, and every major framework ships its own types now anyway.
TypeScript types vs runtime validation
Types vanish at build time, so they cannot save you from a malformed API response or a missing environment variable. These are complements, not competitors. Derive the type from a Zod schema and one definition gives you compile-time checking and a runtime guard.
Gradual migration vs a rewrite
We have never seen a JavaScript-to-TypeScript rewrite finish on schedule, and we have watched several try. Incremental migration reaches the same place: allow JavaScript, convert the files that break most often, tighten the compiler as coverage grows, keep shipping the entire time.
TypeScript, answered
Does TypeScript slow development down?
For about a week, slightly. After that it is faster, because renames and refactors become mechanical instead of archaeological and a whole class of bug never reaches code review. The cost is a build step. The saving turns up in every change request six months later.
Can you convert our existing JavaScript project?
Yes, incrementally. We enable the compiler with JavaScript still allowed, convert the modules with the most churn first, and tighten settings as coverage grows. The application ships throughout. There is no branch that sits open for two months waiting for a big release.
Do you use `any`?
Only at a genuine boundary, and never quietly. Untrusted input is typed as unknown and validated with Zod before anything touches it, so the resulting type describes what was actually checked rather than what somebody assumed on a Tuesday.
Does TypeScript work with our existing backend?
Yes. If the backend publishes an OpenAPI or GraphQL schema we generate the client from it, so the types stay in step without anyone remembering to update them. If it publishes nothing, we write the schema once and validate responses against it.
Does TypeScript affect performance?
No. Types are stripped at build time and the JavaScript that ships is what would have shipped regardless. Bundle size is decided by your dependencies and your code splitting, which is a different conversation and usually a more productive one.
Do you write types for content and configuration too?
Yes. On this site every content file is validated against a Zod schema at build time, so a missing field or a mistyped slug fails the build naming the file and the field, rather than rendering an empty section in production that nobody notices for a fortnight.
Want types across your codebase?
Send the repository. You get a written migration plan with an order of work and an estimate against each stage.