Full Stack Developer (Back-end focused)

• We’re looking for a Full Stack Developer who is analytical, results-driven, and grounded in Java backend development. Your center of gravity will be the backend: designing, building and maintaining the robust, scalable systems that power our SaaS platform in a high-transaction fintech and traveltech environment
• That said, this isn’t a purely backend role. You don’t need to be a frontend expert, but you need to be sharp enough to pick up a ticket that touches the UI, lean on AI to vibe-code your way through the Vue side of it, and get it done properly rather than handing it off. Most of your work will be backend; some of it won’t be, and you should be able to move between the two without friction
• Architecture and APIs
• Design, develop and maintain scalable backend systems using Java
• Build and evolve public and internal APIs, applying best practices in API security and data handling to meet stringent compliance requirements
• Apply Hexagonal Architecture principles to keep systems modular, maintainable and testable
• Data and performance
• Work across relational and non-relational databases, including Couchbase, to design efficient, high-availability data models and queries for high-transaction workloads
• Proactively identify and resolve performance bottlenecks, using observability tools like Datadog to monitor system performance
• Quality and reliability
• Ensure high-quality code through rigorous unit, integration and automated testing, and lead by example in code reviews
• Implement observability practices (metrics, logging, tracing) to monitor system health and catch issues before they become incidents
• Proactively identify technical debt and drive the improvements needed to keep the codebase clean
• Frontend collaboration
• Pick up frontend work in Vue.js when a feature calls for it, leaning on AI to vibe-code the UI side and working end-to-end rather than only on the backend half of a ticket
• Collaborate with the frontend team to keep the product consistent across the stack
• AI-assisted engineering
• Use AI coding assistants (Claude Code, GitHub Copilot and similar) as part of your daily workflow in implementation, testing, debugging and documentation
• Apply Spec-Driven Development: write clear specs up front and use them to guide and validate AI-assisted implementation, so AI-generated code stays reliable and maintainable
• Documentation and collaboration
• Create and maintain technical documentation that supports backend operations and team collaboration
• Work across disciplines to keep the product consistent and the customer experience solid

Benefits

• Fun environment & company events
• Tax-free benefits: Transport, food, gym and childcare
• Flexible hours & Remote work options
• Spacious office in the heart of Barcelona with free coffee & beer
• Competitive salary & progression framework- Bachelor’s degree in Computer Science, Software Engineering or a related field
• A track record designing and implementing large-scale backend solutions in cloud environments, particularly AWS
• Familiarity with build automation tools (Maven, Gradle) and Git-based workflows, including branching, merging and code review
• An analytical mindset, good time management, and a genuine curiosity about new technologies
• Strong debugging and troubleshooting skills, including with asynchronous callbacks, multi-threaded environments and parallel computing Hands-on daily use of AI coding assistants — writing prompts, reviewing AI-generated code, and using them to speed up real work
• Extensive experience in Java backend development, with a solid understanding of the broader product development process
• Strong experience building RESTful APIs and microservices architectures
• Expertise in automated testing (unit, integration, E2E), TDD, and CI/CD pipelines
• A solid grasp of observability tools and practices (e.g., Datadog): metrics, logs, traces
• Proficiency with both relational and non-relational databases (e.g., Couchbase)
• Sharp enough with frontend concepts (Vue.js) to use AI to build or modify a UI feature and know if what comes out is right. You don’t need to be a Vue expert, but you can’t be lost in it either
• Ability to mentor other engineers, run code reviews, and facilitate technical workshops
• Experience in security, compliance or enterprise SaaS environments
• Advanced performance tuning, caching and resource management, including Couchbase indexing and query optimization
• Experience with Nuxt, beyond core Vue