Java Software Engineer
- Posted 02 October 2026
- LocationLondon
- Job type Contract
- Discipline Technology
Job description
Server-side Engineer – Mobile Application Backe
We're looking for a Server-side Engineer – Mobile Application Backend to join our team. In this role, you’ll design and develop the Backend-for-Frontend (BFF) API layer that powers mobile applications used by millions of users worldwide. You will work as part of the Mobile Engineering team—a multidisciplinary group of engineers, designers, and product experts—focused on building intuitive, high-performance backend services that deliver outstanding consumer experiences across digital touchpoints. The ideal candidate brings hands-on server-side engineering experience, strong problem-solving skills, and a passion for writing elegant and scalable code using modern technologies.
Responsibilities
Design, develop, and maintain the mobile service layer (Backend-for-Frontend) supporting large-scale mobile applications
Deliver secure, reliable, and high-performing server-side APIs for real-time consumer experiences
Write clean, maintainable code and contribute to code reviews, refactoring, and continuous improvement initiatives
Collaborate with mobile, product, and design teams to define solutions that enhance usability and functionality
Troubleshoot and optimise application performance for responsiveness and scalability
Create robust unit tests and integration tests to ensure software reliability
Manage asynchronous processing, error handling, and performance optimisation in distributed systems
Support legacy system integrations and modernise existing codebases when required
Follow CI/CD best practices and contribute to team development pipelines and build systems
Actively share ideas, propose improvements, and participate in solution design discussions
Requirements (Must Have Skills)
Proven experience building server-side applications with strong understanding of modern backend development practices
Proficiency in Kotlin or related JVM languages (Java, Scala, etc.)
Practical knowledge of RESTful and GraphQL (GQL) API design and integration
Hands-on experience with Gradle or similar build tools
Solid understanding of asynchronous programming, thread management, and performance optimisation
Experience working with CI/CD pipelines and automated testing frameworks
Strong debugging and problem-solving skills with attention to system scalability and maintainability
Bachelor’s degree in Computer Science or equivalent practical experience
Ability to communicate effectively within cross-functional teams and adapt in fast-paced environments
Nice to Have Skills
Experience designing or integrating RAML-based documentation into API workflows
Familiarity with legacy system modernisation or integration within enterprise environments
Contributions to open-source projects or active involvement in developer communities
Understanding of cloud-native development patterns or containerised deployment workflows (e.g., Docker, Kubernetes)
Creativity and curiosity to explore innovative technical approaches for backend architecture improvements
