Senior Backend Engineer

OUR MISSION IS TO ENABLE EVERYONE TO BUILD WEALTH We reinvent how trading and investing work by creating exceptional products people love. That takes high standards, high velocity and engineers who own what they ship. Today, we serve over 6 million clients, with more than €38 billion in assets under management. At that scale, performance, reliability and data integrity are part of the product. Our platform is powered by a modern, high-performance engineering stack designed for scale and reliability: Java 21 (Spring), Go, Node.js (TypeScript), PostgreSQL, MariaDB, Redis, Kafka, ClickHouse, Elasticsearch, Docker, Grafana, AWS, Kubernetes and Kibana. ABOUT THE ROLE Senior Backend Engineers work across our backend organisation. Your team match will reflect your strengths, interests and where you can contribute most. Across every team, the model is the same: small, autonomous groups, short release cycles and ownership from problem definition through production. WHAT YOU’LL DO - Own backend solutions end to end: understand the business problem, shape the requirements, design the solution, build it, test it, deploy it and run it in production. - Design and evolve services for performance, scale, resilience and data integrity. - Make clear technical decisions with a full understanding of the constraints, alternatives and trade-offs. - Keep code and systems maintainable as products and requirements evolve. - Diagnose difficult production problems, address their underlying causes and prevent recurrence. - Work closely with product and engineering colleagues to turn complex requirements into simple, durable solutions. - Review work critically, share knowledge and raise the engineering standard across the team. WHAT YOU NEED TO HAVE - Solid, hands-on experience delivering backend services in production — you've shipped and operated real systems, ideally within a microservices architecture. - Proven backend engineering experience in Java, which is the core language of our platform. Candidates with strong production experience in Go or Node.js are also encouraged to apply. - Proven ownership of backend services built and operated within a microservices architecture. - Production fluency in at least one modern backend framework (e.g. Spring Boot for Java, or an equivalent in Go or Node.js). - A strong grasp of communication protocols such as HTTP, WebSockets and AMQP, including when to apply each. - Deep knowledge of relational databases, including indexing, transactions, isolation levels, locking mechanisms and high-performance design. - A track record of designing systems for high availability, scalability and resilience. - Clear, structured problem-solving and the ability to explain technical decisions and trade-offs. - Strong engineering fundamentals, sound judgement and confidence learning unfamiliar technologies. Depth in one backend ecosystem and sound tool choice matter more than familiarity with every technology listed. WHAT TO EXPECT - Recruiter conversation - Code Review - System Design - Managerial interview Your recruiter will explain each stage clearly and follow up after every conversation. Bring your ambition to Europe’s fastest-growing mobile broker! We thank all applicants, but only candidates selected for interview will be contacted. All personal data of applicants is protected by law and treated with strict confidentiality.