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.