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Performance Test Engineer

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We are now looking for a Performance Test Engineer, or alternatively a Software Engineer looking to convert to the scientific arts of Performance, to join our RELEX family in Lisbon.

The Performance of our Software, handling in-memory databases of up to billions of data rows and with massive computation requirements, is critical for the company and a differentiating factor versus our competition.

Together with the other members of the Performance Team we will apply the scientific method – hypothesis; experimentation; observation – to explore the Performance characteristics of High Performance Computing servers with up to hundreds of CPU Cores and TiB of Memory, operating in distributed systems.


What you’ll be working on:

  • Expand and maintain existing test frameworks developed in JMeter and create new test frameworks
  • Conduct Performance Testing – follow up on hypothesis raised; experiment them with appropriate test frameworks and load patterns; analyse resulting performance
  • Report findings to development teams and work with them to improve the performance
  • Help deploy and maintain clusters of Linux servers


What you’ll bring to the table:

  • Experience with performance testing or alternatively a solid background as a Software Engineer willing to convert to performance
  • A scientifically minded approach to quality of measurements (accuracy and precision of the measurements); quality of the experiments (isolation of variables); willingness to bounce ideas with colleagues and even peer-review performance work
  • Strong perseverance to conduct investigations to get to the bottom of issues (ex: going through log files searching for error messages; explore different approaches to debugging; etc)
  • Strong communication skills in English (English is our company language)


What we consider as an advantage:

  • Experience with Linux servers or even with performance-optimizing the Linux Kernel
  • Experience with the Java language (preferable) or another Garbage-Collecting language (ex: C#) or even performance-optimizing JVMs
  • Experience with distributed systems (ex: the tools ZooKeeper, Helix, Linkerd, etc)
  • Experience with Grafana, Honeycomb, VMWare, Java Mission Control, or APMs like Dynatrace, AppDynamics, NewRelic
  • Experience with CI pipelines with Gitlab.
  • Experience with InfluxDB.
  • Experience with high-performance Hardware or benchmarking Hardware


What we offer you in return:

  • A sense of purpose for your work. You will know that your daily commitment is effectively reducing CO2 emissions (…and we can measure it)
  • Possibility to be one of the first team members in the Lisbon branch. This means that you will be able to influence the culture and development of the place you will be working at
  • Work-life balance
  • Flexible work hours and a possibility to work remotely
  • An international career and learning opportunities in a rapidly growing software company
  • A fun, ambitious, and committed team of smart people to work with
  • A respectful and professional, yet easy-going atmosphere where individual thinking is encouraged
  • Mobile phone, data plan, health care insurance for you and your family
  • One day per week to work on off-topics (self- development, new ideas…)
  • Competitive salary.


Are you the one we’re looking for? Apply today and become a part of our RELEX family!

You can apply by sending your cover letter and resume through the application form as soon as possible. Please note that we will fill this position as soon as we’ve found the right person, so we recommend that you act quickly.

If you have questions, Ana Raposo (ana.raposo[a] is happy to answer them.



RELEX Solutions is a leading provider of cutting-edge retail optimization software. We offer our customers radically improved demand forecasting and supply chain optimization, which then can be leveraged into exponential benefits — optimizing store space, allocation, workforce, pricing and promotion strategies, all within our unified platform.

RELEX is trusted by leading retail brands including Media Markt, Leroy Merlin, LIDL, Auchan, Dia, Sephora, Douglas, COSTA Coffee, and many, many more, and has offices across North America, Europe, and the Asia Pacific region.