Senior Software Engineer - Java and Search Systems
Role details
Job location
Tech stack
Job description
We're hiring a Senior Software Engineer to join the core Transaction Observability team in Mechelen. You'll work in a small, autonomous scrum team building the engine that ingests, indexes and makes searchable massive volumes of financial transaction data in real time. This is hands-on backend engineering at scale. You'll design and build core features, optimise performance, and influence architectural decisions that directly impact global banks. If you enjoy solving hard data problems and care about writing clean, performant Java - you'll feel at home here. Our stack: Java, Spring Boot, Elasticsearch, Gradle, Kubernetes/Helm. What You'll Do
- Designing and building high-performance backend components in Java
- Real-time ingestion and indexing of large-scale transaction data
- Advanced search capabilities using Elasticsearch
- Performance optimisation and scalability improvements
- Technical design discussions and architectural evolution
- Writing clean, well-tested, production-grade code
Requirements
- Strong Java backend experience, building production systems
- Solid understanding of software design principles and the ability to own technical decisions end-to-end
- Experience with scalable, high-throughput systems
- A product-minded approach - you think about the customer, not just the code
Big Pluses
- Hands-on experience with Elasticsearch or Apache Lucene
- Experience in fintech, regtech, or financial messaging
- Exposure to high-volume, real-time data systems
Benefits & conditions
- Your code ships to production at some of the world's largest banks - this isn't internal tooling that nobody notices
- The scale is real - real-time search across billions of financial messages
- Small team, high ownership - you shape technical decisions, not just execute tickets
- Modern delivery pipeline - GitHub Actions, ArgoCD, continuous delivery to soak testing instances - so you can ship with confidence
- AI-augmented development - we use Claude Code as part of our daily workflow, so you spend more time on hard problems and less on routine work
- Hybrid work with an office five minutes from Mechelen station
- International, English-speaking engineering team
- Competitive compensation including Belgium's federal mobility budget
We welcome applications from candidates who have the right to work in Belgium. Visa sponsorship is not available for this role.