Mathieu Decaffmeyer

Product-Focused Full-Stack Software Developer

About me

I bring over 15 years of experience in developing modern, globally competitive web and mobile solutions that deliver an exceptional user experience.

I can work autonomously to deliver complete products or seamlessly integrate with your team, on-site in Brussels or remotely.

I have extensive experience with object-oriented principles, and in recent years, I’ve shifted toward the functional paradigm. My work spans backend, frontend, and mobile app development. Having worked across multiple paradigms, servers, browsers, and various languages and frameworks, I’ve gained a strong grasp of core design principles, system architecture, and best practices for building maintainable and scalable code.

I excel at identifying potential issues early, addressing root causes, recognizing bad practices before they escalate, and ensuring strong test coverage to keep applications easy to change and extend.

Here are a few principles that resonate with me and steer my approach to work:

  • Focus on the user, not the product.
  • Design for change, keep it easy to adapt.
  • Simplify wherever possible, minimize complexity.
  • Write code for people, not machines.

Beyond my technical expertise, I encourage a supportive, enjoyable work environment.

Outside of my main work, I’m an active contributor to open-source projects.

Professional Experience

Full-Stack Software Developer
Pocomos

Feb 2024 – present

Develop and enhance a SaaS application for pest control companies, enabling agents to efficiently manage schedules and routes, and allowing sales teams to track leads and revenue.
React Native/PHP/Symfony/VueJS/MariaDB/Rest/HTML/CSS

Full-Stack Software Developer
Subtile

Mar 2023 – Feb 2024

Developed a finance tracking tool for NGOs from scratch, covering backend, frontend development, UI/UX design, and deployment.
Elixir/SolidJS/PostgreSQL/GraphQL/HTML/CSS

Full-Stack Software Developer
MoneyTransfer

Mar 2022 – Mar 2023

Evaluated application complexity and new developer onboarding challenges. Recommended improvements and reported on technical debt's business impact to the CTO and founders. Provided coaching on design principles and best practices.
Elixir/PostgreSQL/Rest

Full-Stack Software Developer
CitizenLab

Aug 2020 – Nov 2021

Developed a real-time application to increase citizen involvement in government projects, enabling discussions, voting, and idea sharing via video conferencing and interactive forms.
Elixir/LiveView/PostgreSQL/HTML/CSS

Full-Stack Software Developer
Multipharma

Apr 2017 – Mar 2019

- Developed a React-based stock management app from scratch to efficiently track and manage daily medication packets for resthome clients.
- Building various internal-use web apps to optimize pharmacists' internal workflows and processes.
React/Rest/HTML/CSS

Full-Stack Software Developer
ING

Jan 2017 – Apr 2017

Migrating ING's website to a modern, responsive design for improved user experience and accessibility.
JavaScript/PHP/HTML/CSS

Full-Stack Software Developer
Multipharma

Dec 2015 – Jan 2017

- Refactoring critical legacy, buggy applications for the delivery of daily medication packets to rest home patients, ensuring each packet's content and timing are accurate.
- Building various internal-use web apps to optimize pharmacists' internal workflows and processes.
PHP/jQuery/Oracle DB/HTML/CSS

Full-Stack Software Developer
Freelancing

Jan 2008 – Dec 2015

- Building presentation websites for clients in various sectors.
- Developing an application for doctors, enabling online appointment bookings and automated email and SMS reminders for patients.
PHP/jQuery/MySQL/HTML/CSS

Full-Stack Software Developer
Fortis

Sep 2006 – Jan 2008

Develop an internal Java web application for booking seats on a private airplane shuttle between Brussels and Luxembourg, featuring seat selection and flight scheduling.
Java/Struts/JavaScript/Oracle DB/HTML/CSS

Full-Stack Software Developer
Ebuco

Mar 2006 – Jun 2006

Create an app for remote management of digital displays in businesses, featuring easy upload and scheduling of ads and media and real-time updates.
Java/Swing/MySQL

Education

Computer science
Institut Paul Lambin

Oct 2003 – Jun 2006

About me

Name

Mathieu Decaffmeyer

Age

41 y/o

Languages

English, French, Dutch

Contact me

Design is not just what it looks like and feels like. Design is how it works.

—Steve Jobs