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NR.Niels Rigter

Freelance TypeScript developer for reliable web apps

I help as a freelance TypeScript developer with applications where types are not an afterthought. Less guesswork in production, clearer contracts between UI and API, and a codebase that remains followable later.

What problem does this solve?

JavaScript scales until your team grows or the app gets more complex. Then you feel it: silent type errors, vague API responses, and features that 'work' until someone hits an edge case.

TypeScript is not a checkbox. Poorly applied, it mostly adds noise: `any` everywhere, types that are too strict for anyone to maintain, or types so loose they catch little. Applied well, it prevents production debates.

I use TypeScript end-to-end in Next.js projects: frontend, server actions or API routes, data models, and integrations. Types follow the business rules, not the other way around.

Looking for TypeScript capacity without an agency: direct collaboration with someone who keeps both product flow and type architecture sharp.

Who is this for?

  • Teams that want to strengthen a JavaScript app with TypeScript
  • Startups that want to build type-safe from day one in Next.js
  • Product teams seeing regressions from unclear data contracts
  • Companies that want to improve or extend an existing TypeScript codebase
  • Organizations that need temporary full-stack TypeScript reinforcement

What I concretely do

  • TypeScript setup and conventions a team can sustain
  • Type-safe UI, API, and data layers in Next.js / React
  • Shared types or schemas for forms, responses, and domain models
  • Refactoring loose JavaScript or weak typing into useful types
  • Code that compiles and remains readable for a future team

Approach

  1. 01

    1. Risks and scope

    We look at where errors currently emerge: UI, API, data, or integrations. Then we decide what type safety needs to solve first.

  2. 02

    2. Contracts and foundation

    Domain models, response shapes, and shared types are set early. That keeps frontend and backend speaking the same language.

  3. 03

    3. Build or tighten

    Deliver new features type-safely, or improve existing parts step by step without rewriting everything at once.

  4. 04

    4. Handover

    Conventions, examples, and clear boundaries documented in the code itself, so types keep helping instead of getting in the way.

Technologies

TypeScriptNext.jsReactZod / schema validationDrizzle ORMPostgreSQLAPI routes / server actionsNode.js

Example from practice

In product apps with roles, statuses, and external APIs, TypeScript prevents UI and backend from drifting apart. I set shared types and validation so errors become visible early: at compile time or at the request boundary, not only after a user complaint.

For product apps that will grow, I strongly recommend it. For very small, short-lived scripts, plain JavaScript can be enough. For web apps that will stick around, TypeScript is usually the better foundation.

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