Principal Backend Engineer -Fintech Scale Up - Java Kotlin

Our client is a London based Fintech scale up with operations across Europe, Asia and South Americas. This role requires candidates to work 2 day per week in London office. Job Responsibilities: Own architecture for critical, scalable cloud-native platforms supporting payments experiencesBuild secure, resilient, compliant services for high-volume transaction processingDrive modern backend practices using Java 17/21, Spring Boot 3, Kotlin, and clean architectureDesign event-driven architecture with Kafka across scalable, decoupled domainsDefine standards for API-first development, REST/gRPC, and domain-driven design (DDD)Set standards for availability, performance, fault tolerance, and observabilityTranslate business priorities into scalable technical strategy with Product, Data, and leadershipLead cross-functional technical initiatives supporting growth and market expansionJob Requirement: 10+ years building and operating distributed, production-grade backend systemsSenior Staff or Principal experience driving architecture across teams or domainsDeep expertise in Java (17+), Spring Boot, and modern backend engineeringStrong experience with microservices, event-driven architecture, and asynchronous systemsExperience with high throughput, low latency, reliability, ideally in fintech or transaction-heavy environmentsStrong system design, data structures, and performance trade-offs knowledgeProduction experience with AWS, Docker, and KubernetesExperience with observability, resilience patterns, and CI/CDStrong stakeholder communication, influence, and senior engineering mentorship Robert Walters Operations Limited is an employment business and employment agency and welcomes applications from all candidates