Senior Software Engineer - Wise Platform - API Experience

About the API Experience Team The API Experience team builds and maintains some of the most critical systems at Wise: the public API gateway, authentication/authorization systems (OAuth2), SDKs, and developer infrastructure used by our partners and internal teams. Our goal is to set the gold standard for intuitive, secure, and enterprise-ready financial APIs. You will solve complex challenges around scaling microservices across our network of 700+ microservices, optimising developer experience for global banks, ensuring financial-grade security, and enabling seamless integration at scale. What You Will Be Doing Design & Architecture: Architect, build, and maintain highly scalable backend services using Java, Spring Boot, Kafka, and PostgreSQL within an event-driven, microservices architecture. API Product Ownership: Set API standards (RESTful, OpenAPI/Swagger, OAuth2) and build developer-friendly tools, SDKs, and reference implementations to reduce integration complexity for major partners. Technical Leadership & Mentorship: Champion engineering best practices, conduct code reviews, participate in domain modeling (DDD), and mentor junior engineers across the team. Cross-Functional Collaboration: Partner closely with Product Managers, Implementation Managers, Solutions Engineers, and partner development teams to define features, shape technical solutions, and influence product strategy. Cross-Organizational Impact: Work across frontend and infrastructure stacks, helping decentralized engineering teams across Wise align with API standards and architecture patterns. Global Travel: Collaborate directly with engineering hubs across the globe, including travel to our Tallinn office.   What You Need to Succeed Public API Experience: Proven track record of designing, building, and maintaining production-grade public APIs (RESTful APIs, OpenAPI/Swagger, OAuth2). Core Backend Stack: Extensive experience with Java and Spring Boot for building resilient backend microservices. Distributed Systems & Data: Hands-on experience with event-driven architecture (Kafka or similar messaging systems) and relational database design/optimization (PostgreSQL, MySQL). Architectural Knowledge: Proficiency in domain-driven design (DDD), microservices patterns, and building for high availability and low latency. Product Mindset: A customer-centric approach to engineering—balancing technical excellence with business context, user experience, and cost efficiency. Communication & Collaboration: Ability to convey complex technical concepts to non-technical stakeholders, collaborate across business units, and adapt to feedback. Nice to Have Experience with financial-grade security standards, compliance requirements, or international payment systems (FX, funding, settlement, interbank networks). Familiarity with frontend frameworks or infrastructure/gateway tooling. Experience maintaining open-source developer libraries, SDKs, or…