Senior Java Software Engineer

Principal Java Engineer Location: Hybrid — London We're currently partnered with a fast-growing technology company operating in the payments space, processing high-volume transactions at scale who are looking for a Principal-level backend engineer to help own and evolve the architecture behind their most critical platforms. What You'll Do Own and drive architecture for platforms that scale with the business and unlock new capabilitiesDesign and evolve high-scale, cloud-native systems powering payments and merchant experiencesLead development of resilient, secure, and compliant services for high-volume transaction processingChampion modern backend practices (Java 17/21, Spring Boot 3, Kotlin, clean architecture)Architect event-driven systems (Kafka) enabling scalable, decoupled domains across teamsDefine standards for API-first development (REST/gRPC) and domain-driven designSet the bar for availability, performance, fault tolerance, and observabilityPartner with Product, Data, and leadership to translate priorities into technical strategyLead cross-organisational initiatives critical to company growthMentor senior engineers and bring structure to ambiguity across technical and regulatory domains What You Bring 8+ years building and operating distributed, production-grade backend systemsTrack record operating at Senior Staff / Principal level across multiple teams or domainsDeep expertise in Java (17+), Spring Boot, and modern backend practicesStrong experience with microservices, event-driven architecture, async systemsExperience with high throughput, low latency systems — fintech/transaction-heavy environments a strong plusSolid grounding in system design, data structures, performance trade-offsHands-on production experience with AWS, Docker, KubernetesExperience implementing observability, resilience patterns, CI/CD best practicesStrong communication skills and ability to influence senior stakeholdersExperience mentoring engineers and leading through ambiguity The Role Flexible hybrid workingHealth insuranceMeal allowance25 days annual leave + bank holidaysPublic transport allowanceRegular team events If this role is of interest, apply here or email dounia.hardwicke@exploreltd.com for more information