System Design Engineer Senior

About the Role

We're looking for a Senior System Design Engineer to join a key financial project in Brussels. In this role, you'll translate complex business needs into scalable technical solutions, support the operation of mission-critical platforms like Fidessa, Fusion, UL Bridge, and help drive continuous improvement in a dynamic trading environment.

This is a hands-on engineering role, ideal for someone with strong system architecture knowledge, troubleshooting expertise, and a keen interest in trading systems or financial markets.

Key Responsibilities

Translate business requirements into robust technical designs, considering trade-offs and feasibility.

Validate compliance and ensure implementation aligns with specifications.

Analyze and optimize system performance, capacity, and scalability.

Investigate and resolve incidents, perform root cause analysis, and produce technical documentation.

Contribute to on-call support for critical systems.

Maintain and upgrade key trading-related platforms : Fusion , Fidessa , and UL Bridge .

Collaborate with internal teams and third-party vendors on technical issues and system improvements.

Support and troubleshoot FIX protocol -based messaging (experience with FIX is a plus).

Must-Have Skills & Experience

5+ years in system design, software integration, or IT infrastructure roles.

Strong skills in troubleshooting, incident management, and root cause analysis.

Solid technical writing / documentation skills.

Knowledge of JavaScript , Jira , and open systems (Linux / Unix) .

Excellent communication and problem-solving abilities.

Independent, proactive, analytical, and team-oriented mindset.

Fluent in Dutch and English (both required).

Nice to Have

Experience with : Confluence , IBM MQ , MySQL , or Sophis .

Background in trading platforms, capital markets, or financial technology.

Profile

Bachelor's or Master's degree in IT, Software Engineering, Business Management, or equivalent experience.

Proven ability to act as a bridge between business users and technical application teams.

Self-driven, solution-oriented, and eager to grow in a financial / trading environment.