Senior Software Engineer – Java Backend London (5 days onsite, with some ad-hoc flexibility) £85,000 – £120,000 (Permanent) TechHeads is currently seeking a Senior Software Engineer with strong Java backend experience, DevOps awareness, and proven technical leadership capabilities to join our Client’s London team. This is a high-impact role involving the design, development, and deployment of backend services that power our client’s security platform. You’ll work on systems at significant scale, leading both engineering efforts and mentoring team members, while collaborating with globally distributed teams in the US, Ireland and India. Responsibilities: Design, develop, and maintain Java-based backend services using Spring Boot , REST/GraphQL , Kafka , PostgreSQL , and RabbitMQ . Contribute to infrastructure modernisation efforts, working closely with DevOps teams on Kubernetes , CI/CD pipelines , and legacy system migrations. Innovate across the stack, taking ownership of key projects and delivering performant, scalable solutions. Lead engineering best practices including coding standards, unit testing, code reviews, and system architecture discussions. Support, coach, and mentor junior developers, fostering a culture of technical excellence and collaboration. Work closely with cross-functional teams, including product and engineering groups in the US, Ireland and India, to ensure alignment and execution. Build and deploy secure, resilient APIs (REST/GraphQL) and optimise the full software development lifecycle through automation. Requirements: 7–10 years of professional experience in software engineering, with a strong focus on Java backend development . Solid understanding of Spring Boot , Kafka , RabbitMQ , PostgreSQL , and modern API design patterns. Hands-on experience or familiarity with DevOps tools and concepts – e.g. Kubernetes , Git-based CI/CD , cloud infrastructure (AWS/GCP/Azure). Bonus: Exposure to tools like Elasticsearch/Kibana , Hadoop/HBase , OpenSearch , or VPN/proxy architectures. Strong grasp of software security principles , system performance optimisation, and infrastructure reliability. Experience working on large-scale , production-grade systems with distributed architectures. Ideal Candidate will: Bring technical vision , initiative, and a passion for exploring and implementing emerging technologies. Are a natural technical leader with experience mentoring engineers and driving engineering quality across teams. Enjoy solving complex problems and have a product mindset with an eye toward continuous improvement.