Twikey

Twikey builds software for automating recurring payments: digital contract and mandate signing, SEPA direct debit processing, invoicing logic, and integrations with European banks and accounting systems. The company is looking for a Senior Back-end Engineer to improve and extend the core platform. You will work with the CTO and a small engineering team on production challenges including performance, correctness, data modelling, integration workflows, and system reliability. The role is hands-on and technical with emphasis on clean code, maintainability, and measurable improvements. Key responsibilities: improving backend performance (queries, caching, algorithms, data flows); designing and implementing new backend features; keeping the codebase clean, testable, and maintainable; working on integrations with banks and third-party systems; reviewing code and reducing complexity; contributing to release processes in an Agile environment. Requirements: 5+ years professional experience with Java + Spring; strong experience with PostgreSQL; comfortable improving performance and understanding system behavior under load; writes clean, structured, testable code; communicates clearly and works well in a small team; fluent in at least two of Dutch / English / French. Nice to have: API integrations, webservices, Linux, fintech/banking domain knowledge. Stack: Java, Spring, Go, PostgreSQL, REST APIs, Linux. Front-end uses Angular / Svelte.