Senior Backend Engineer - Java / Architecture (Remote)

About the role

Watu, a fintech company operating across Africa and Latin America, is hiring a Senior Backend Engineer (Java / Architecture) for its Technology organisation. The role reports to the Tech Lead of the assigned squad and is fully remote. You will own a domain end-to-end inside a squad of 4-6 people, bringing architectural opinions, raising the quality bar for colleagues and taking responsibility for the reliability and maintainability of what you build.

Key responsibilities

• Design, build and maintain backend services and APIs used by other squads, external partners and customer-facing products.
• Write unit and integration tests as part of development, not as a separate phase.
• Drive architecture discussions, propose designs, write Architectural Decision Records and defend technical choices.
• Review pull requests deeply, assessing design, maintainability, performance and test coverage.
• Write and maintain technical documentation such as API specs (OpenAPI), service READMEs and runbooks.
• Contribute to shared libraries and platform standards, and use AI/LLM tooling actively in your workflow.

Required profile

• 5+ years of professional backend software engineering experience, including at least 3 years in Java in production at a design-decision level.
• Deep knowledge of REST API design and relational database design, including schema, indexing and query optimisation.
• Distributed systems experience: eventual consistency, idempotency, retry logic, circuit breakers and failure mode design.
• Testing with JUnit/Mockito and integration tests against a real database.
• Preferred: event-driven architecture (Kafka), microservices, AWS, Kotlin, fintech or payments experience.

Required skills

• Java and Spring Boot (dependency injection, Spring Security, Spring Data, transaction management, Spring Test)
• REST API design and relational database design
• JUnit, Mockito, OpenAPI/Swagger
• Preferred: Kafka, AWS, Kotlin

To apply, send your CV and a brief note on why you want the role to the Watu talent team. The process includes an initial conversation with the Head of Engineering, a technical interview and a final conversation with the wider leadership team.