Contract Software Engineer (Java & Kotlin)

Company: Spectrum IT Recruitment
Apply for the Contract Software Engineer (Java & Kotlin)
Location: London
Job Description:

Senior Java & Kotlin Backend Engineer

Location: London (Hybrid – Wednesday office attendance required)Contract: Initial 2 monthsIR35: Outside IR35Start Date: ASAP

The Role

We’re working with a leading technology organisation seeking an experienced Senior Java & Kotlin Backend Engineer to join their engineering team on an initial two-month contract.

This role offers the opportunity to contribute to greenfield backend development, building scalable, cloud-native microservices within a modern engineering environment. You’ll work alongside cross-functional teams to design, develop and deliver high-quality backend solutions that are secure, reliable and built for scale.

Key Responsibilities

  • Design, develop and maintain backend services using Java and Kotlin.

  • Build and enhance RESTful APIs within a microservices architecture.

  • Develop secure, scalable and high-performance applications.

  • Collaborate with Product Managers, Engineers and technical stakeholders to deliver new features.

  • Participate in code reviews and contribute to engineering best practices.

  • Improve system reliability, performance and scalability.

  • Work with cloud-native technologies and modern deployment practices.

  • Support production systems and contribute to continuous improvement initiatives.

Essential Skills & Experience

  • Strong commercial experience with Java and Kotlin.

  • Proven experience developing applications using Spring Boot.

  • Strong understanding of microservices architecture.

  • Experience designing and building REST APIs.

  • Commercial experience with Kafka or similar messaging technologies.

  • Experience with PostgreSQL.

  • Experience working with AWS cloud services.

  • Hands-on experience with Docker and containerised applications.

  • Strong understanding of software engineering best practices, testing and CI/CD.

  • Excellent communication and problem-solving skills.

Desirable

  • Experience with Gradle.

  • Experience working within Agile development teams.

  • Knowledge of distributed systems and event-driven architectures.

Contract Details

  • Initial 2-month contract.

  • Outside IR35.

  • Hybrid working with office attendance in London every Wednesday.

  • Immediate start available.

Spectrum IT Recruitment (South) Limited is acting as an Employment Business in relation to this vacancy.

Posted: July 20th, 2026