Mid weight Kotlin / Java Server-Side API Engineer - Contract Opportunity - London Hybrid
NO SPONSORSHIP OFFERED
Role Overview
We are looking for a Server‑Side Engineer to help build and enhance the service layer (Backend‑for‑Frontend) that powers large‑scale mobile applications used by millions of global customers. This role is ideal for someone who enjoys solving complex engineering challenges, working with modern technologies, and contributing to high‑quality backend systems that directly impact user experience.
You’ll be joining a collaborative team of engineers, product managers, designers, and QA specialists, working together to deliver fast, reliable APIs that support feature‑rich mobile app experiences.
What You’ll Do
Develop and maintain Backend‑for‑Frontend (BFF) services that support large‑scale mobile applications.
Use Kotlin (primary) and Java (secondary) to build clean, maintainable, well‑tested backend components.
Work closely with cross‑functional teams to implement new features and improve existing functionality.
Contribute ideas, share best practices, and help drive continuous improvement within the engineering team.
Apply and responsibly leverage AI/LLM‑based development tools to enhance productivity, accelerate learning, and improve code quality.
Participate in code reviews, technical discussions, and architectural decisions.
About You
Strong foundation in JVM backend engineering, with hands‑on experience in Kotlin and Java (approx. 70/30 split).
Used AI tools commercially and and happy to discuss this in interviews.
Enjoys tackling challenging problems and writing clean, well‑structured, and maintainable code.
Curious, proactive, and comfortable sharing ideas in a collaborative environment.
Passionate about high‑quality backend services that improve mobile user experiences.
Familiar with modern development tools and comfortable using AI‑assisted workflows responsibly.
Technologies & Tools
Kotlin (primary language)
Java
Gradle
REST APIs
GraphQL
Location
London, UK
Rate/Salary
280.00 - 300.00 GBP Daily
Trading as TEKsystems. Allegis Group Limited, Maxis 2, Western Road, Bracknell, RG12 1RT, United Kingdom. No. (phone number removed). Allegis Group Limited operates as an Employment Business and Employment Agency as set out in the Conduct of Employment Agencies and Employment Businesses Regulations 2003. TEKsystems is a company within the Allegis Group network of companies (collectively referred to as "Allegis Group"). Aerotek, Aston Carter, EASi, Talentis Solutions, TEKsystems, Stamford Consultants and The Stamford Group are Allegis Group brands. If you apply, your personal data will be processed as described in the Allegis Group Online Privacy Notice available at (url removed)>
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