Backend Java Developer

Backend Java Developer Location: Sheffield (Hybrid)

Employment: Fixed Term Contract

Salary: £50,000 – £60,000 base (dependent on experience) If your idea of backend engineering is more than CRUD APIs and microservices boilerplate — this role is for you. We’re building the core backend services of a Data Fabric platform that governs data access, entitlements, and query policy enforcement across distributed enterprise data systems.

This is platform engineering: deterministic rule engines, SQL planning/interception, and high-throughput services that sit on the critical path of data access.

This is deep backend + data infrastructure work.

🚀 What You’ll Do

Build core backend services in Java (17/21) for access control and query manipulation

Implement deterministic policy / rule engines for data governance

Work on SQL parsing, planning, validation, and transformation (e.g., Calcite or similar planners)

Integrate with distributed data platforms / query engines (e.g., Starburst or similar)

Own API contracts with living documentation in CI/CD

Build production-grade, testable pipelines

Drive observability, reliability, and performance

Contribute to architecture decisions (modularity, DI, extensibility)

What You Bring (Must-Have)

Strong hands-on experience in Java (17/21) + Spring

Deep understanding of JDBC, SQL parsing/validation, query planning/optimization

Experience with SQL planners or query transformation layers

Strong grounding in data structures, algorithms, and backend performance

Production-grade testing using JUnit 5, Mockito

Experience with clean architecture, DI, modular design

Comfortable owning CI/CD, code quality, observability

Familiarity with Docker, Maven, Jenkins

⭐ Nice to Have

Apache Calcite

Starburst or federated query engines

JVM performance tuning

High-throughput service interfaces (REST/gRPC)

Data governance or policy enforcement layers

👥 This Role Is Ideal If You’ve Worked On

Data platforms, governance layers, query engines, or SQL planners

Backend/platform services that sit in the critical path of data access

Systems where correctness, determinism, and performance matter