Java Kotlin Lead

Java/Kotlin Team Lead – London – 6 months – Circa £650pd – 3 days pw

We are partnered with a tech client who are looking for a Lead Backend Engineer with strong experience in Java and/or Kotlin to take a key technical leadership role within a backend-focused engineering team

Technical Leadership & Influence

• Lead design discussions, technical deep dives, and knowledge-sharing initiatives
• Anticipate technical risks and proactively propose scalable, secure solutions
• Influence product and platform decisions through strong technical insight

Hands-on Software Development

• Develop high-quality backend services using Java (17+) and frameworks such as Spring Boot or Micronaut
• Build resilient, high-throughput services supporting secure transaction processing
• Design and implement integrations with external systems including payment gateways, banks, and fraud platforms

Core Skillset:

• Proven experience as a Lead Java Engineer in backend-heavy, multi-level engineering teams
• Strong expertise in Java 17+, with Spring Boot or Micronaut; Kotlin experience is a bonus (or willingness to learn)
• Hands-on experience with event-driven architectures, Kafka, microservices, and enterprise integration patterns
• Solid understanding of payment systems and PSP integrations, including fraud, tokenisation, and settlement flows
• Experience with cloud infrastructure (Azure preferred), Kubernetes, and CI/CD pipelines
• Working knowledge of relevant regulatory standards such as PCI DSS, SCA, and PSD2s
• Experience working in Agile/Scrum environments with a DevOps and test-driven mindset

Nice to have

• Experience with IAM platforms such as Okta, Auth0, Keycloak, or ForgeRock
• Knowledge of identity and security standards including OpenID Connect, OAuth2, JWT, SAML, and MFA
• Broader cloud exposure across Azure, AWS, or GCP

If this is of interest, please send an updated CV and we can set up a call?

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