Realtime Backend & API Engineer (Kotlin/Java)

Korn Ferry; City Of London; On-site; GBP 70,000 - 100,000; Full time

Job summary

Korn Ferry is looking for an experienced backend engineer to design, develop, and maintain server-side APIs for large-scale mobile applications. You will work across teams to define scalable solutions and contribute to CI/CD pipelines while ensuring performance and reliability.

Requirements include strong Kotlin/ JVM language skills, REST and GraphQL API experience, and a solid background in asynchronous programming and testing. The role emphasizes code quality and collaboration.

Qualifications

• Proven experience building server-side applications with strong back-end practices.
• Proficient in Kotlin or related JVM languages.
• Experience with RESTful and GraphQL APIs.
• Hands-on experience with Gradle or similar build tools.
• Strong debugging and performance optimization skills.
• Experience with CI/CD pipelines and automated testing frameworks.

Responsibilities

• Design, develop, and maintain the mobile service layer (Backend-for-Frontend) for large-scale apps.
• Deliver secure, reliable server-side APIs for real-time consumer experiences.
• Write clean code and participate in reviews, refactoring, and continuous improvement.
• Collaborate with mobile, product, and design teams to define usable solutions.
• Troubleshoot and optimize performance for responsiveness and scalability.
• Create unit and integration tests to ensure reliability.
• Follow CI/CD practices and contribute to pipelines and build systems.
• Share ideas and participate in solution design discussions.

Skills

Kotlin

Java

Scala

REST API

GraphQL

Gradle

Async programming

CI/CD

Testing

Distributed systems

Performance

Debugging

Tools

Docker

Kubernetes

Job description

Korn Ferry is looking for an experienced backend engineer to design, develop, and maintain server-side APIs for large-scale mobile applications. You will work across teams to define scalable solutions and contribute to CI/CD pipelines while ensuring performance and reliability.

Requirements include strong Kotlin/ JVM language skills, REST and GraphQL API experience, and a solid background in asynchronous programming and testing. The role emphasizes code quality and collaboration.