Senior Solution Architect – Rail Traffic Planning

Senior Solution Architect for the train and works planning applications at a railway infrastructure manager in Brussels. Time & material, December 2026 to November 2031. Fluent English and French or Dutch required.

Description

We are looking for a Senior Solution Architect to design and govern the architecture of the train and works planning solution at a railway infrastructure manager in Brussels. The assignment is on a time & material basis, full-time, and starts preferably on 1 December 2026 for an estimated 9,000 hours. You have at least 10 years of experience, including as a solution architect on production systems, you model in ArchiMate, and you speak fluent English and French or Dutch.

The applications are used by train and works planners, signal box staff and traffic control. They are critical for rail operations and covered by a 24/7 on-call service. You are not part of a development team and you report to the team lead.

Technology: OpenShift, AIX, Oracle and Redis; Java 8 and Java 17-21 (mostly microservices); Angular 15 and 18, and Swing; HashiCorp Vault; IBM MQ and Kafka; Elastic. Experience with one specific technology matters less than assessing a new one quickly. The coexistence of legacy and microservices, and of MQ and Kafka, is the core difficulty of the domain.

• Design, document and govern the solution architecture, in line with enterprise architecture, principles, standards and target roadmaps
• Translate functional and non-functional requirements into a feasible, secure, resilient and scalable design
• Build and compare several scenarios, with benefits, costs, risks and reversibility, including a rough implementation cost per scenario
• Record key decisions in Architecture Decision Records
• Make a technical inventory of the solution and a technical architecture roadmap that covers the current state, the legacy maintenance, the platform modernisation programme and cybersecurity standards
• Plan the transition: gaps, intermediate states and realistic migration steps
• Keep the architecture repository in ArchiMate, in one model with views per stakeholder (for example in Sparx EA)
• Prepare architecture reviews, handle deviations and run conformity reviews during the build and before go-live
• Guide the design, development, integration, test, cybersecurity and operations teams; join refinement and do targeted code reviews on service boundaries, interface contracts and transaction and error handling
• Contribute to proofs of concept where technical risk calls for it
• Hand over architecture knowledge and keep the documentation up to date

Your profile

Required:

• At least 10 years of experience in IT, engineering or a related field
• At least 10 years as a solution architect on production systems and in designing information systems
• Experience designing and integrating solutions across several technical domains and stakeholders
• Enterprise and solution architecture, governance and requirements management
• Reasoning in scenarios, trade-offs, risks, dependencies, costs and value
• Knowledge of integration patterns, APIs, data, infrastructure, cloud and cybersecurity
• Understanding of resilience, continuity, performance, capacity and lifecycle in operations
• Experience in architecture reviews, risk analyses and guiding implementations
• Distributed application architectures: service boundaries, transaction boundaries, data ownership, interface contracts and versioning, events and messaging
• Hands-on software development experience, recent enough to be credible with an engineering team
• Fluent English and French and/or Dutch, spoken and written
• Clear communication with technical and non-technical people, facilitation and negotiation, and the ability to get an architecture decision accepted by explaining it rather than imposing it

Preferred:

• Practical knowledge of TOGAF (5 years); a TOGAF certification is a plus
• Knowledge of security practices and of an IT service management framework

Nice to have:

• Contribution to relevant iterations of the architecture development method, without taking over enterprise strategy or overall governance

Assignment

• Time & material, full-time
• Location: Brussels
• Estimated volume: 9,000 hours
• Start: preferably 1 December 2026
• End: 30 November 2031
• Rate: to be discussed