Senior Non-Functional Engineer

Railz

Railz

Diegem, 1831 Machelen, Belgium
Posted on Oct 14, 2025

Position Type :

Full time

Type Of Hire :

Experienced (relevant combo of work and education)

Education Desired :

Bachelor of Computer Science

Travel Percentage :

5 - 10%

The world of finance moves fast. At FIS, we’re faster. Our teams are empowered to learn, grow, and make an impact–in their careers and communities. We deliver innovation that advances the way the world pays, banks and invests. If you want to grow personally and professionally, we’d like to know: Are you FIS?

About the role:
As a Senior Non-Functional Engineer (NFE) / Performance Engineer based in Belgium, you will join a team of 10+ senior engineers distributed across the globe. The team is responsible for the non-functional aspects of various projects and products built on the Open Payment Framework (OPF) platform.

About the team:

You'll be part of an expert team in performance testing for OPF and CBIS products serving all our customers.

What you will be doing:

  • You will be involved in all phases of the project/product life cycle, starting from the definition of the Non Functional Requirements, the definition of the acceptance tests, the execution and reporting of them, the coaching of developers/architect on how to best code/design the solution to meet performance goals, the investigations (problem and solution) of performance problems on all tiers of a deployed solution (Application server, Web server, DB, JMS engine, network, storage) in FIS Labs.

  • Open Payment Framework is a J2EE based framework working on WebSphere and Open Liberty, Linux/AIX with MQ or SIBUS as JMS engine and Oracle or PostgreSQL as DB engine.


What you will need:

  • Relevant experience in performance tuning (algo, java, SQL,...)

  • Excellent (developer) knowledge of java/j2ee with hands on mentality

  • Willing to learn and use FIS standards reporting/tools

  • High level of autonomy

  • Sound knowledge of HA/DR

  • Experience on WebSphere and OpenLiberty

  • Good knowledge of Linux

  • Good knowledge of cloud (Azure, AWS, OpenShift, K8S, ...)

  • Experience with Oracle/PostgreSQL

  • Experience with MQ/SIBUS

  • Use of a Java profiler (e.g., JProfiler), AWR, debugger, and nmon.


Added bonus if you have:

  • Experience in payments environment or worked in banking projects.


What we offer you:
At FIS, we hire the best. In return, you receive exceptional benefits including:

  • • Opportunities to innovate in fintech

  • • Tools for personal and professional growth

  • • Inclusive and diverse work environment

  • • Resources to invest in your community

  • • Competitive salary and benefits

#LI-Hybrid #LI-RB1

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Sourcing Model

Recruitment at FIS works primarily on a direct sourcing model; a relatively small portion of our hiring is through recruitment agencies. FIS does not accept resumes from recruitment agencies which are not on the preferred supplier list and is not responsible for any related fees for resumes submitted to job postings, our employees, or any other part of our company.

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