Senior Software Engineer

Principal Engineer (Java / Event-Driven) — Financial Markets, London London / hybrid — 3 days per week in office Please note: visa sponsorship is not available for this role A major London exchange is rebuilding the systems behind its global reference pricing and cross-venue volatility controls, bringing a critical estate back in house after years of vendor dependence. This is a genuine build programme, not maintenance, and we're looking for a Principal Engineer to help lead it. The role This is a senior individual contributor position (no people management). You'll drive technical direction, architecture, and hands-on delivery of business-critical pricing platforms, systems that sit at the heart of the exchange and cannot fail. You'll design, build, test, and own services end to end, embedding with operations and the business rather than working purely heads-down. There's real autonomy here to make design decisions in your own space and drive projects from concept to delivery. What you'll bring Significant hands-on Java engineering, building and operating distributed systemsDeep experience with microservices, APIs and event-driven architecture (Kafka)Kubernetes and cloud-native delivery, with strong DevOps practice across CI/CD, IaC and automated testingThe judgement to lead design discussions, weigh trade-offs pragmatically, and make sound engineering decisionsA breadth-first mindset: strong systems thinking matters more here than narrow specialismThe maturity to work autonomously and communicate clearly with technical and non-technical stakeholders Nice to have Experience in financial services, trading or other regulated environments; SRE practice; observability tooling (Prometheus, Grafana, Splunk, OpenTelemetry, Elastic); active open-source contribution. Why it's worth a look Modern, open-source-friendly engineering culture with AI tooling being rolled out, meaningful ownership of critical infrastructure, and the chance to shape a greenfield in-housing programme from the front.