Senior Java Engineer (Outside IR35) – Kafka & Spring Boot

Senior Java Engineer – Kafka & Spring Boot About the Client We’re working with an innovative team building the next generation of secure, real-time communication and data platforms. Their flagship product is a fresh reimagining of an existing system, crafted to provide robust, distributed coordination for a wide range of uses – from emergency response and humanitarian logistics to private collaboration and secure deployments in highly regulated or sensitive contexts. Location & Flexibility Office attendance is flexible. Come in as much or as little as you like. They have a well-equipped London office if you’d like a change of scene, but in-person attendance is only occasionally required for team meetups or workshops – always with advance notice. The Role We’re looking for a Senior Java Engineer who thrives in the world of Kafka and Spring Boot. You’ll play a key role in crafting a secure, distributed backend system designed for real-time operations and maximum resilience. You’ll team up with infrastructure, AI, and frontend specialists to create reliable backend services that keep people and teams connected when it matters most. Your Day-to-Day ️ Architect and build event-driven microservices using Java, Spring Boot, and Kafka Be responsible for the backend engineering for secure, distributed real-time systems Design and deliver rock-solid APIs in collaboration with frontend and AI colleagues Seamlessly integrate with identity and access management tools (like Keycloak) Champion observability best practices through effective logging, metrics, and tracing Pitch in on architecture decisions and mentor your peers to keep code quality top-notch Define secure development practices fit for sensitive, regulated environments What You’ll Bring 10+ years of experience as a backend or systems engineer working with Java Proven track record of designing and running Kafka-based systems at scale Mastery of the Spring Boot ecosystem, including modules for Security, Web, and Data Expertise in building event-driven systems that deliver high reliability and performance Familiarity with message schemas (Avro, Protobuf) and strategies for evolving events Experience integrating with identity systems like Keycloak Strong grasp of system-level concerns like observability, availability, and resilience Background working in secure, regulated, or mission-critical environments Comfortable working with CI/CD pipelines, IaC tools, and containerised deployments Security Clearance This role requires the ability to gain UK SC clearance. If you’re eligible, they’ll support and fast-track your clearance. If you already have it then even better. Bonus Points If You’ve Worked With: ✨ Graph-based, messaging, or synchronisation systems ✨ Zero-trust or encrypted transport architectures ✨ Tools like Vault, WireGuard, or advanced key management ✨ Distributed coordination, stateful services, or geo-redundant deployments Why Join? Contribute to a mission-driven product that makes a real-world impact Work in a high-trust, supportive engineering culture Enjoy flexibility and autonomy – your work, your way Competitive salary and equity Direct access to decision-makers and a say in shaping the future of the platform Ready to build something that matters? Please apply At Pixelated People, we don’t just do inclusion and diversity. We embrace people that have different opinions, perspectives and personalities. Because we believe that by seeing the world from all sorts of angles, we can make life better for all the people who live in it. So we want you to know that the things that make you, you — like your age, ability, background and identity — are things that we celebrate and support.