Kotlin/Java Backend Engineer - Mobile APIs (INSIDE IR35)

We are looking for experienced Kotlin/Java Backend Engineers to join a major financial services organisation, working on the Back End services supporting large-scale iOS and Android mobile applications used by millions of customers worldwide., * Design, develop and maintain scalable Back End services and APIs.

• Build Backend for Frontend (BFF) solutions supporting mobile applications.
• Develop high-quality code using Kotlin and/or Java.
• Work with REST APIs, microservices and existing enterprise Back End systems.
• Participate in code reviews, testing, debugging and performance optimisation.
• Collaborate with engineering, architecture, product and QA teams.
• Contribute to CI/CD pipelines, monitoring and continuous improvement.
• Support technical architecture and mentor engineers where appropriate.

• Strong hands-on Back End development experience with Kotlin and/or Java.
• Experience developing REST APIs and microservices.
• Familiarity with Spring/Spring Boot.
• Experience with Maven or Gradle.
• Understanding of CI/CD, automated testing and software development best practices.
• Experience working in Agile engineering environments.
• Strong problem-solving and communication skills.

Desirable Experience:

• Java 17+
• Backend for Frontend (BFF) architecture
• Domain-Driven Design (DDD)
• GitHub Actions/CircleCI
• Dynatrace, ELK or Sentry
• GraphQL/RAML
• Technical leadership, solution design or mentoring experience