Expert Test Engineer

🚀 Freelance Expert Test Engineer | Brussels | Hybrid

For a major organisation in the public sector, we are looking for an experienced Expert Test Engineer to join a large-scale digital modernisation programme.

📍 Location: Brussels

📅 Start: 1 December 2026

⏳ Duration: 12 months, with possible extension

🏢 On-site: 3 days/week in Brussels

💻 Remote: 2 days/week

🗣️ Languages: Dutch or French + English

👤 Level: Expert – 10+ years of professional experience

🎯 The role

You will join an experienced and highly skilled Agile delivery team working on a major digital transformation programme involving cloud, APIs, microservices, Zero Trust and event-driven architecture .

As an Expert Test Engineer, you will be responsible for defining, designing and implementing the overall test strategy and ensuring the quality of the solution through a high level of test automation.

This is a hands-on engineering role . We are specifically looking for someone who has personally implemented and worked with the required technologies and testing practices, not someone whose experience is limited to managing or coordinating teams.

🔴 MUST-HAVE REQUIREMENTS

• 10+ years of professional experience as a Test Engineer
• 5+ years hands-on experience with test automation
• 5+ years hands-on experience with API testing , preferably Bruno
• 5+ years hands-on experience with UI testing , preferably Cypress
• Good knowledge of HTML DOM
• 5+ years experience with regression and integration testing , preferably JUnit & Cucumber
• 5+ years experience with performance, stress and load testing , preferably JMeter & Gatling
• 5+ years experience with E2E testing
• 5+ years experience with CI/CD pipelines and test integration , preferably Azure DevOps
• 5+ years experience with contract testing, mocking and service virtualisation
• 5+ years experience with monitoring & observability , preferably Grafana
• 5+ years experience with scripting , preferably Python and/or JavaScript
• 3+ years hands-on Java SE 10+ development experience
• 3+ years experience with SQL databases
• 5+ years experience working in Agile delivery teams
• Experience with cloud-native environments
• Experience with APIs and microservices
• Ability to independently design and implement test strategies and automation

🌟 NICE-TO-HAVE

• Experience designing and developing APIs
• Experience developing and integrating microservices
• Experience with cloud, API and event-driven software architecture
• Experience with event-driven architectures
• Knowledge of BDD / Event-Driven Development
• Knowledge of Domain-Driven Design (DDD)
• Experience within a federal/public-sector environment

🗣️ LANGUAGES – MUST HAVE

English: good professional level

AND either Dutch OR French: good professional level

You must be comfortable working in a bilingual environment and communicating with both technical and non-technical stakeholders.

🎓 EDUCATION

A higher-education degree in Computer Science / IT from a recognised university or university college within the European Union is mandatory.

👤 PROFILE

We are looking for a pragmatic, hands-on Test Engineer who:

• Takes ownership from analysis through design and implementation
• Is passionate about software quality and test automation
• Can challenge existing approaches and propose alternative solutions
• Communicates effectively with technical and business stakeholders
• Works well within multidisciplinary Agile teams
• Is comfortable working on-site 3 days per week in Brussels

⚠️ Please note: This is not a pure management, coordination or consulting assignment. The role requires significant hands-on technical implementation .