Software Engineer BackEnd Senior Onshore (m/f/d)

Halian | Managed Services, Recruitment Agency & Contract Staffing; Brussel; On-site; EUR 90,000 - 130,000; Full time

Job summary

Halian Group in Brussels is seeking an experienced Mainframe Developer to join its IT team. You will translate business requirements into technical designs and develop, maintain, and modernize mainframe applications in a collaborative, multi-stakeholder environment.

You will work closely with IT and business partners, participate in on-call rotations, and contribute to continuous improvement and modernization while ensuring stability of critical services.

Qualifications

• Strong hands-on experience in mainframe development and maintenance.
• Understanding of mainframe programming, databases, development workbenches, source control, and CI/CD practices.
• Ability to translate complex business needs into functional/technical solutions.
• Excellent written and verbal communication; ability to explain ideas clearly.

Responsibilities

• Translate business requirements into functional and technical designs.
• Develop, maintain, and enhance mainframe applications.
• Work independently to understand existing applications and processes.
• Participate in on-call support rotation for critical services.
• Collaborate with IT and business stakeholders across teams.
• Contribute to modernization and continuous improvement while maintaining existing solutions.

Skills

Mainframe development

CI/CD

Communication skills

Dutch and English

Tools

Source control

Development workbenches

CI/CD tools

Job description

A leading organization operating in the financial services sector is seeking an experienced Mainframe Developer to join its IT team. The role focuses on developing and maintaining business-critical applications, translating business requirements into technical solutions, and working effectively within a complex and collaborative environment.

Responsibilities

• Translate business requirements into clear functional and technical designs.
• Develop, maintain, and enhance applications within a mainframe environment.
• Work independently to quickly understand existing applications, processes, and functional requirements.
• Participate in an on-call support rotation to ensure continuity of critical services.
• Collaborate closely with both IT and business stakeholders across different teams.
• Contribute to modernization and continuous improvement initiatives while maintaining existing solutions.

Qualifications and Skills

• Strong hands‑on experience in mainframe application development and maintenance.
• Solid understanding of mainframe programming, database concepts, development workbenches, source control, and continuous integration/deployment practices.
• Ability to translate complex business needs into effective functional and technical solutions.
• Strong communication and interpersonal skills, with the ability to explain ideas in a clear and structured manner.
• Ability to work effectively and autonomously in a complex environment involving multiple stakeholders; strong team‑player mindset.
• Excellent Dutch and English communication skills; experience within financial markets or investment‑related environments is considered an advantage.

Halian Group

With over 28 years of experience, we have come to understand that innovation is the only way to provide agile, practical solutions that transform businesses and careers.

Our resourcing and smart services help you to realize tomorrow’s potential. Discover the amazing things possible when you bring the right people and the right technologies together.

At Halian, we recognize that diversity, equity, and inclusion (DEI) are essential to building high‑performing teams for our clients. We are committed to connecting organizations with top talent from all backgrounds, ensuring that every individual feels valued, respected, and empowered to contribute their unique perspectives. We encourage applications from all qualified candidates, regardless of race, gender, disability, or any other characteristic that makes them unique. By fostering diverse and inclusive workplaces, we help our clients drive innovation, enhance collaboration, and better reflect the communities they serve.

Software Engineer BackEnd Senior Onshore in Brussels, Belgium