Java Engineer - Backend - Distributed Systems
London, UK - Excellent
Contract
Posted by
Rothstein Recruitment Ltd
Applicants must be eligible to work in the specified location
Java Engineer - Backend - Distributed Systems
Excellent opportunity opens for talented Java Developers to join a Globally leading Financial Services entity, working on critical, new projects.
Role overview
We are hiring Back End Java engineers to work on large-scale, event-driven platforms processing high volumes of Real Time transactions and API traffic. The environment is fully reactive and non-blocking, built for throughput, resilience, and low latency. This is not traditional Spring MVC/CRUD development. The stack is based on reactive streams and distributed data stores.
Key responsibilities
- Build and maintain reactive microservices using Project Reactor (Flux/Mono)
- Develop APIs and services using Spring WebFlux and non-blocking I/O
- Design and optimise data models on Apache Cassandra for scale and resilience
- Work with event-driven architectures (typically Kafka or similar messaging)
- Focus on performance, fault tolerance, and horizontal scalability
- Collaborate with platform, SRE, and data teams on production systems running at scale
Required experience
- Strong Java Back End engineering background (Java 11+)
- Hands-on production experience with Project Reactor and reactive programming
- Experience building services with Spring WebFlux (not only Spring MVC)
- Experience working with Cassandra or other distributed NoSQL databases
- Understanding of:
- Non-blocking I/O
- Backpressure
- Reactive threading models
- Experience in high-throughput, low-latency systems (payments, trading, telco, fintech, large-scale APIs)
Desirable experience
- Kafka or other streaming platforms
- Reactive database drivers (eg, reactive Cassandra, R2DBC)
- Cloud platforms (AWS, GCP, or Azure)
- Kubernetes and containerised deployments
- Observability in reactive systems (metrics, tracing, resilience patterns)
Interested? Please Apply!
London, UK
IT
ASAP, will await notice
12 months initial Duration
Excellent
Rothstein Recruitment Ltd
Will Buckner
JS/MRL/WB/JAVACONTRACTORS
22/01/2026 10:50:26