Java/Kotlin Backend Developer

Are you driven by innovation and ready to create the future of banking? At GFT, we're teaming up with DKB group to launch a tech hub in Valencia, focused on developing sustainable, next-generation software. Be part of a pioneering team that will reshape the banking industry. As a technical backbone for our compliance-driven customer lifecycle domains - including Personal Master Data, Tax & Exemption Orders, and Power of Attorney - you take ownership of the stability and evolution of our Spring Boot-based APIs. By expertly navigating between high-throughput Reactive Kotlin and stable Spring MVC architectures, you deliver performant solutions within a complex regulatory landscape. You thrive in a high-trust environment, bridging technical excellence with precise domain logic to ensure the highest standards of data integrity and regulatory compliance for our customers. If you’re looking for an exciting challenge and the chance to grow your career, we want to hear from you!

Your main responsibilities will be:

• Comprehensive Knowledge Integration & Handover: Successfully complete the structured handover process from the existing team, demonstrating a deep technical understanding of both the Reactive and MVC Spring Boot stacks, as well as the functional intricacies of the Person Master Data, Tax, and Power of Attorney domains.
• Full Operational & Development Autonomy: Transition to a state of full independence where you can autonomously design, implement, and maintain complex features and bug fixes across both APIs without relying on the previous team for domain or technical guidance.
• Regulatory Compliance by Design: Ensure that 100% of code contributions regarding tax regulations, exemption orders, and power of attorney legalities meet strict internal and external compliance standards, evidenced by successful security and audit reviews.
• Production Stability & Incident Ownership: Take full ownership of the operational health of the managed services, including participating in resolving production incidents to maintain uptime and performance.
• Technical Debt & Performance Optimization: Actively identify and execute strategic improvements within the inherited codebase - such as refactoring legacy logic or optimizing reactive streams - to enhance the long-term maintainability and scalability of the systems.
• Collaborative Stakeholder Alignment: Establish a proactive working relationship with the Product Owner and Engineering Manager, effectively translating business requirements into robust technical solutions while transparently communicating technical constraints and risks.
  
  

Required Skills:

• Asynchronous Kotlin & Coroutines: Deep expertise in Kotlin and Spring Boot, with a focus on non-blocking architectures using Coroutines (e.g., with Netty). You understand how to write efficient, readable asynchronous code that scales under high load.
• Cognitive Flexibility: The mental agility to jump between different technical paradigms (Coroutines vs. MVC) and complex domain topics (Tax vs. Power of Attorney) without losing momentum.
• Robust API Design & Lifecycle Management: Advanced skills in designing RESTful APIs that are scalable and well-documented (JSON:API Specification via Open API Specification). You understand the importance of backward compatibility in a large-scale ecosystem.
• Evolutionary API Design (Backward Compatibility): Since our APIs do not use explicit versioning, you possess the discipline and skill to evolve services backward-compatibly. You understand how to manage the lifecycle of fields and endpoints, ensuring a smooth grace period and clear communication for consuming clients.
• Quality-First Engineering (Testing): You view automated testing as a prerequisite for deploying stable code in a sensitive domain. Expertise in building a comprehensive safety net using Unit, Integration, and Acceptance Testing. While our focus is on these core layers, you have an interest in (or experience with) Contract Testing, helping the team decide if and when to re-introduce it to stabilize client-provider relationships.
• Security & Compliance by Design: The ability to translate GDPR and regulatory requirements (Tax, Power of Attorney) into technical constraints. You don’t just build features; you build secure, auditable, and compliant systems.
• Architectural Contextualization: Beyond writing code, you understand the "why" behind the architecture. You can "read" the existing architecture, understanding the nuances of the inherited logic to ensure that your new contributions don't break existing client integrations. You can navigate and document the existing codebase, identifying patterns and potential improvements.
• Self-Driven Ownership: During the onboarding and handover, you are a proactive learner who seeks out information to reach full autonomy quickly, treating the inherited code with respect while driving its improvement.
• Analytical Precision: Given the high stakes of Tax and Power of Attorney domains, you possess a keen eye for detail. You are thorough in your logic, ensuring that edge cases in legal requirements are handled correctly.
• Resilience in Complex Environments: You remain calm and focused when dealing with legacy code or production incidents, treating challenges as opportunities for system improvement rather than just "problems to fix."
• Active Collaboration & Knowledge Sharing: You are a team player who understands that our success depends on collective knowledge. You actively engage in Pair Programming, thorough Code Reviews, and documentation. You don't just solve a problem; you ensure the whole team understands the solution to prevent knowledge silos.
• Constructive Feedback Culture: You contribute to a high-trust environment by giving and receiving feedback openly and respectfully. You see technical discussions as a way to find the best solution, not as a personal competition.
• Commitment to Professional Growth: You take ownership of your development. You stay curious about evolving technologies (e.g., new Kotlin features or Spring updates) and are eager to master the complexities of our domains (Tax, Power of Attorney). You leverage the diversity of our tech stack as an opportunity to broaden your architectural mindset.
• Language Proficiency: Fluency in English (minimum B2 level); German language skills are a plus.

Preferred Skills:

• Bachelor’s Degree in Computer Science, Engineering, or related field.
• Expertise in Java (Spring, Spring Boot) and microservices architecture.
• Strong understanding of Agile methodologies and an interest in the banking and asset management industry.

Soft skills:

• Fluent communication skills.
• Team player: ability to work with teams distributed geographically in different locations.
• Solid analytical and problem-solving skills/investigating skills on technical matters.
• Well organised.
• Good time management and prioritization of tasks
• Ability to identify problems and suggest mitigating and contingency actions.
• Proactive, motivated and willing to learn and develop oneself.

What we offer:

• Work-Life Balance and Flexibility: Option to work in a hybrid setup, flexible schedules, and compressed Fridays.
• Training and Development: Personalized plan and training programs.
• Social Benefits: Meal vouchers, life insurance, telecommuting support.
• Flexible Compensation: Adapted to your needs (health insurance, childcare, training, among others).
• Relocation Package (if applicable): Financial support, guidance, visa sponsorship.
• Referral Program.
• Wellness Program: Nutrition, Physical, Mental. Discounts with Gympass.
• Life at GFT: Smart offices, events, values awards, inspiring talks.
• International Corporate Culture.

At GFT we consider diversity as one of our main pillars and we foster an inclusive work environment based on cooperation and mutual respect. We offer equal opportunities for everyone regardless of race, cultural background, gender, age, sexual orientation, gender identity, disability or religious beliefs. GFT has drafted and registered an Equality Plan that outlines the measures to be taken with the aim of achieving equal treatment and opportunities between women and men within the company, and eliminating, if present, discrimination based on gender.

Join our Global Team!