Backend Engineer — Java

Kolomoni Microfinance Institution (Gambia) is a CBG-licensed microfinance institution serving customers across The Gambia. We are recruiting a Backend Engineer to build and maintain the services our products run on.

THE ROLE You will design, develop, test, deploy and maintain secure, scalable backend applications — the business logic, APIs, integrations and data processing behind our customer-facing products. The work is judged on what survives production: correctness under load, safety under failure, and code the next engineer can maintain. You will report to the Chief Technology Officer.

WHAT YOU WILL DO

Design and develop secure, scalable, maintainable APIs and application business logic in Java.

Design database structures and data-access components, and optimise application and database interactions.

Apply transaction and concurrency management, and idempotency where an operation must not run twice.

Build applications that handle retries, duplicate requests and partial failures safely.

Implement authentication, authorisation and application-security controls, and protect sensitive data in transit, at rest and in logs.

Develop logging, monitoring and audit capability sufficient to reconstruct an incident.

Write and maintain automated tests, participate in peer review, and resolve production defects.

Requirements

WHAT WE ARE LOOKING FOR

Substantial hands-on experience building and maintaining production backend services in Java.

Spring Boot or an equivalent framework, relational databases and SQL, and REST API design.

Understanding of asynchronous and event-driven architecture, caching, and application security.

Git, automated testing, containerisation and modern deployment.

A first degree in computer science, engineering or a related discipline, or demonstrable equivalent experience.

Experience in financial services or payments — where correctness under failure matters more than speed of delivery — is an advantage.

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