Senior Test Specialist-ATR000299

Location: Brussels Belgium
Start Date: 9 November 2026
Duration: Until 9 November 2028 with potential extension
Work Regime: Full-time
On-site: Minimum 2 days per week with additional on-site presence when required

We are looking for a Senior Test Specialist to join a testing team responsible for planning and executing System Acceptance Testing (SAT) supporting functional testing defect analysis and test activities across multiple business and application domains.

The role requires a strong technical and functional testing background with the ability to work effectively in both Waterfall and Agile/Scrum environments. The successful candidate will collaborate closely with functional analysts test coordinators technical teams and vendors.

• Plan prepare and execute sanity regression and functional tests.
• Write detailed and effective test scenarios and test cases.
• Execute existing test scripts and support semi-automated regression testing.
• Perform functional testing across application and integration changes.
• Analyse document and follow up on defects according to priority.
• Perform first-line defect analysis for major releases.
• Execute SQL queries for test preparation validation and investigation.
• Test integrations using SOAP UI XML and related interfaces.
• Review and understand Technical Design Documents including if/then/else logic.
• Support testing across message exchange batch processing and infrastructure-related changes.
• Provide input to improve test techniques test coverage and execution approaches.
• Challenge product quality and identify potential issues particularly around integrations.
• Participate in Agile/Scrum testing activities where applicable.
• Support knowledge transfer and onboarding within the testing team.
• Organise and participate in alignment meetings and daily stand-ups.
• Collaborate closely with analysts test coordinators test managers and vendors.
• Execute ad-hoc testing requests when required.

• Minimum 7 years of experience as a Functional Tester.
• Minimum 5 years of experience as a Test Specialist.
• Proven experience writing test scenarios.
• Strong knowledge of formal test methods and techniques.
• Proven experience with Waterfall testing methodology.
• Proven experience in Agile/Scrum testing or relevant Agile testing training.
• Strong experience with:
  • DevOps
  • VBScript
  • SOAP UI
  • XML
  • SQL
• Proven ability to write and execute simple and complex SQL queries.
• Experience reading and understanding Technical Design Documents including if/then/else logic.
• Proven experience within the Belgian energy sector.
• ISTQB Foundation certification or higher.
• English proficiency at minimum CEFR C1 with the ability to communicate fluently in English.
• Dutch or French proficiency at minimum CEFR C1.
• Strong analytical and problem-solving skills.
• Proactive critical and quality-oriented mindset.
• Ability to work collaboratively within a multidisciplinary testing team.

• Experience with test automation.
• Additional experience with Agile testing methodologies.
• Experience supporting integration testing and complex enterprise applications.
• Experience providing knowledge transfer or mentoring to other testers.

The successful candidate should be:

• Proactive and eager to learn new business and application domains.
• Comfortable working independently while actively supporting team members.
• Critical in assessing product quality and test coverage.
• Collaborative in working with analysts technical teams and vendors.
• Flexible in working across both Waterfall and Agile/Scrum approaches.
• Focused on continuous improvement of testing processes and quality.

The role requires a minimum of 2 working days per week on-site in Brussels. Additional on-site attendance may be required for project needs meetings onboarding knowledge transfer security requirements or other operational reasons.

Occasional travel to other offices or third-party locations may also be required.

The candidate is expected to provide their own laptop equipped with up-to-date security software.

Functional Testing SAT Testing Test Scenarios Test Cases Regression Testing Sanity Testing Defect Management Waterfall Agile/Scrum SOAP UI XML SQL DevOps VBScript Technical Design Documents Test Automation ISTQB Belgian Energy Sector