TaxTim · Lead developer

A new interface for a mature tax platform

Consultancy through Leaply · February–August 2026

The problem

A new product interface still needs to work with the business behaviour in the existing system. At TaxTim, the work connected a React and TypeScript UI overhaul to a mature Symfony application through a new v2 API.

My contribution

As lead developer on this consultancy engagement through Leaply, I led and implemented most of the UI overhaul and the API that powers it. My contribution spanned frontend architecture, product decisions, backend integration, and verification.

The work, at a glance
  1. 01React + TypeScript UI
  2. 02v2 API contracts
  3. 03Existing Symfony platform

Simplified illustration of the work, not a system specification.

How I approached it

I focused on sustainable development: composable code, explicit API contracts, automated testing, and modern engineering practices. The interface and backend changed together, with tests checking existing behaviour and clear boundaries making the code easier to understand and maintain.

What the work enabled

The overhaul connected a new React interface to the established Symfony platform through a v2 API. Just as importantly, it gave future development a more maintainable foundation through composability and testing.

React · TypeScript · PHP / Symfony · REST APIs · Automated testing

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