One of our clients is looking for a freelance Performance Tester with strong UI automation and API testing skills. The role is based in Antwerp (province).
They are seeking a highly experienced performance testing specialist who can design, script, execute and analyse performance tests across web, mobile and API-based applications. The ideal consultant combines strong technical expertise with a proactive mindset and excellent communication skills.
Practical details:
* Start date: February 2026 (asap)
* Duration: Outcome 2026 with possible extension (3 months confirmed)
* Regime: Fulltime
* Location: Antwerp (province)
* Office days: Monday & Thursday
Key Responsibilities
* Script end‑to‑end UI user flows for web and mobile applications using Apache JMeter.
* Design, develop and execute comprehensive performance test scenarios for web, API and mobile applications.
* Maintain clear linkage between test scenarios, scripts and non‑functional requirements (NFRs).
* Prepare and manage performance test data, including creation of datasets and supporting teams with data needs.
* Work with both standalone and distributed JMeter environments, including Docker‑based setups.
* Execute load, stress, volume and endurance tests.
* Collect detailed technical input from developers and solution architects.
* Build realistic workload models, gather stakeholder feedback, and obtain approval ahead of execution.
* Produce performance test execution reports using JMeter Dashboards, including deep‑dive analysis and recommendations.
* Use monitoring and observability tools such as Dynatrace for analysis and troubleshooting.
* Define environmental scalability and extrapolation aligned with production environments.
* Take ownership of performance scripts and maintain existing assets.
* Register, track and follow up performance‑related defects with development teams.
* Provide structured progress reporting to the Delivery Manager and maintain accurate status in Jira.
Required Skills & Experience
* Minimum 5+ years of hands‑on performance testing experience.
* Strong scripting skills (Java).
* Solid experience with Apache JMeter for UI and API performance testing.
* Strong analytical thinking, attention to detail and technical autonomy.
* Excellent communication skills in English, knowledge of Dutch is a plus.
* Ability to work independently in a complex technical environment.
Education
* Bachelor’s or Master’s degree in Computer Science, ICT/IT, or a related technical discipline.
Nice to Have
* Experience in a telecommunications environment.
* Knowledge of CI/CD pipeline integration for performance testing.
* Familiarity with additional monitoring/performance analysis tools.