Freelance Mainframe Architect Jobs (NOW HIRING)

• Locations Belgium Poland United Kingdom France Netherlands

Division: Group Business Solutions (GBS)

Your career opportunity

Join our Group Business Solutions (GBS) division, where we design and sustain IT solutions for financial market securities. Be part of a dynamic, collaborative team in a fast‑evolving environment, shaping the future of financial technology.

Ready to make an impact?

We’re seeking a skilled and proactive Lead Expert Software Engineer to drive meaningful improvements across our solutions. You’ll collaborate across teams, provide technical and functional leadership, and guide key initiatives that enhance our systems and processes in an innovative, growth‑oriented environment aligned with business needs.

• Lead end‑to‑end design, architecture, and delivery of large‑scale, mission‑critical systems, owning highly complex features and cross‑team initiatives. In this context, you are accountable for the definition and the realization of end‑to‑end architecture solutions that satisfy the functional, non‑functional, security and resilience requirements. From the inception phase until deployment, you collaborate with the Requirement Owners and the Domain Architects, and you lead the IT software engineers and application authorities across the organization.
• Shape technical strategy, influencing architectural decisions and ensuring alignment with organizational goals. Participate actively to the development of the Solution Architecture and Software Engineering practices in Euroclear, contributing to establish solution patterns and building blocks that can be reused by the IT community. Contribute to the definition of domain target architectures and roadmaps.
• Mentor engineers across levels, guiding complex problem solving and elevating technical standards.
• Drive definition, estimation, and validation of highly complex technical requirements across multiple teams.
• Anticipate cross‑team dependencies, improve planning accuracy, and drive predictable, high‑quality delivery through strong technical leadership and collaboration.
• Ensure production stability by leading complex investigations, driving long‑term solutions, and improving troubleshooting practices.
• Proactively identify and address systemic risks to improve operational resilience.
• Champion and evolve engineering best practices and coding standards, improving code quality, engineering effectiveness, and driving innovation.

What you need to have to succeed in this role:

• Solid experience as a Lead Software engineer (at least 15 years in the IT industry) on large‑scale transformation projects ( > €10 MM EUR), crafting, developing, and deploying critically important transactional systems in large and complex organizations.
• Deep understanding of software related system architectures and designs.
• Expert knowledge of solution development and core design principles.
• Expertise in translating complex business requirements into scalable solutions, ensuring alignment with enterprise standards and long‑term strategy.
• Experience in IBM Mainframe and Windows .NET and Java development stacks as well as a good command of Azure Cloud, APIs, Integration mechanisms and Data technologies in general.
• Nice to have:
  • Experience with tools such as: IntelliJ IDEA, Eclipse, JDK, Javac/Java commands, Maven, Gradle, IDE environments, JUnit, Git, Docker, CI/CD pipelines (Jenkins, GitHub Actions), Prometheus, Grafana, OpenTelemetry, VisualVM, JFR, Kubernetes, Azure Cloud, AWS, GCP, VPC/VNet, CLI, Visual Studio, Oracle, CSS, SSIS, APIs, MQ Series, Linux.
  • Experience with programming languages such as: Angular, C#, .NET, ASP.NET Core, Java, Spring Boot, SQL, REST, COBOL, PLI, Perl, PHP, Python, PowerShell.
• Strong command of English, both spoken and written.

What makes you stand out:

• Experience in the Financial Services industry and knowledge of the related regulatory environment and Knowledge of post‑trade market infrastructures (e.g. CSD).
• Knowledge of Enterprise Architecture frameworks (e.g. TOGAF, ArchiMate).
• Knowledge of Agile methodologies.
• Background in Machine Learning, Data Science, or Generative AI.

We welcome applicants from all backgrounds and experiences. If you meet most of the requirements and are excited about the role, we encourage you to apply.

Please note that this is a permanent position, and we do not offer freelance or contract arrangements for this role.

• Work closely with inspiring, supportive and engaged colleagues from more than 80 different countries.
• Practice your talents in a highly professional international environment.
• Join a learning and development environment with an emphasis on knowledge sharing and training.
• Competitive salary and comprehensive benefits.

Ways of working: Find your own optimal balance within our hybrid working model, where you can connect at the office 8 days a month and also benefit from remote working.

Great Place to Work for All. We are committed to creating an inclusive culture that celebrates diversity and strives to be a Great Place to Work for All. All qualified applicants will be considered for employment, regardless of any aspect that makes them unique (including race, religion, national origin, gender, sexual orientation, age, marital status, pregnancy, disability, ...). If you need any specific accommodation due to disability or any other reason, you can let the recruiter know during your application process.