[Hiring] Senior Backend Engineer @Watu

Role Description

Senior Backend Engineer at Watu means owning a domain end-to-end inside your squad - and influencing how that domain evolves. You write code, but you also shape the system. You bring architectural opinions that the Tech Lead can rely on, you raise the quality bar for the engineers around you, and you take full responsibility for the reliability and maintainability of what you build.

We use Java as our primary backend language, but we do not hire Java developers who only think about Java. We hire engineers who happen to use Java. The difference matters: we want people who can reason about distributed systems, design clean APIs, think about failure modes before they happen, and care about the downstream consumer of their code as much as the implementation.

You will be embedded in a squad of 4–6 people. Your Tech Lead is your primary technical counterpart and reviewer, but at the senior level the expectation is that you operate with significant autonomy. You are not waiting to be told what to build or how to solve a problem - you bring a point of view, surface design decisions proactively, and contribute to the direction of your domain.

What You Will Do

• Design, build, and maintain backend services and APIs consumed by other squads, external partners, and customer-facing products.
• Write unit and integration tests as a first-class part of development - not as a separate phase, not as something the QA engineer handles for you.
• Drive architecture discussions within your squad - propose designs, write Architectural Decision Records, and defend technical choices clearly.
• Review pull requests with depth and directness, assessing design, maintainability, performance, and test coverage.
• Write and maintain technical documentation: API specs (OpenAPI), service READMEs, runbooks for systems you own.
• Contribute to shared libraries and platform standards when your work has cross-squad value.
• Use AI/LLM tooling actively in your workflow - code generation, test writing, debugging, documentation.

Qualifications

• 5+ years of professional backend software engineering experience, with at least 3 years working in Java in a production environment.
• Java and Spring Boot depth - understanding of the framework, dependency injection, Spring Security, Spring Data, transaction management, and testing with Spring Test.
• REST API design - knowledge of good API practices (versioning, error handling, idempotency, pagination).
• Relational database design - schema design, indexing, query optimisation, and understanding performance implications.
• Distributed systems depth - proven experience with eventual consistency, idempotency, retry logic, circuit breakers, and failure mode design.
• Testing - unit tests with JUnit/Mockito, integration tests with a real database.

Requirements

• Event-driven architecture in production - Kafka or equivalent.
• Microservices architecture experience - service discovery, API gateways, inter-service communication patterns, distributed tracing.
• Cloud environment familiarity - particularly AWS.
• Experience with any additional JVM language (Kotlin) or willingness to learn.
• Fintech, payments, or financial services domain experience.

Benefits

• Competitive salary and performance-based bonuses.
• Flexible working hours and remote work options.
• Professional development opportunities.
• Health and wellness programs.

How to Apply

Send your CV and a brief note on why this role to the Watu talent team. We run a structured process: an initial conversation with the relevant Head of Engineering, a technical interview, and a final conversation with the wider leadership team. We move quickly for the right candidate.

We are an equal opportunity employer and actively work to build a team that reflects the diversity of the markets we serve.