Hi! I'm Cas Cornelissen,
a creative full-stack developer based in Tilburg, The Netherlands.

  • TypeScript
  • React
  • Sass
  • Node.js
  • Bun
  • Vite
  • Webpack
  • Vitest
  • Jest
  • Cypress
  • Playwright
  • Docker
  • Kubernetes
  • CI/CD
  • GitHub
  • GitLab
  • AWS
  • Cloud-native development
  • Open-source software

Projects

SVG Spritemap Webpack Plugin

  • 2016 – current

Open-source Webpack plugin that generates a single optimized SVG spritemap from a directory of icons, with support for inlining, variables, and accessibility attributes.

Event Hooks Webpack Plugin

  • 2016 – current

Open-source Webpack plugin that lets developers hook arbitrary code into any of Webpack's compiler events, useful for build automation and lightweight tooling.

Home

  • 2018 – current

Self-hosted platform built around a custom Home Assistant front-end with SSO-based user management and additional modules for recipes, media, and household tooling.

Ecorus Model Runner

  • 2025

Platform built around an in-house simulation model. Users configure inputs, trigger runs, follow live progress, and explore results through an interactive dashboard.

Qontinu Coaching

  • 2020

Performance-focused static website for a Dutch life and career coach, designed to feel personal and approachable while staying fast and easy to maintain.

Optis Executive Consultants

  • 2017

Technical implementation of a multi-language WordPress-based website for Optis, with a custom theme and editor experience tailored to their content workflow.

Experience

Wärtsilä

  • 2019 – current

Lead Front-end & UX Developer for the Digital Research & Development department, building asset management products for the marine and energy industries. Responsible for architecture, design system, and developer experience across a portfolio of cloud-native applications.

Freshheads

  • 2015 – 2019

Front-end Developer on projects for Centraal Beheer, Interpolis, and YoungOnes, working across the stack from React applications to CI/CD pipelines with a healthy dose of DevOps along the way.

Onefinity

  • 2015 – current

Founder of Onefinity, the company I run for freelance and open-source work, focusing on web development, tooling, and the occasional side project.

2manydots

  • 2012 – 2015

Front-end and WordPress Developer building custom themes and editorial websites for clients including Nessos, Tommy de Lange Fotografie, and Abrahams Hoveniers.