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# Java Developer - JSON/JSLT/Drools

- **Company:** Synergize Consulting Ltd
- **Location:** London, United Kingdom
- **Salary:** £118,300 - £145,600
- **Contract:** Temporary contract
- **Skills:** Java (Programming Language), Acceptance Test-Driven Development, Automation of Tests, Drools, JSON, Secure Coding, Systems Integration
- **Published:** November 8, 2026
- **Apply:** https://www.careerboard.com/gb/en/find-jobs-in-United-Kingdom/-296EB8457620ADB3CE/

## About the Role

* Strong commercial Java development experience.
 * Hands-on experience with JSON, JSLT and Drools.
 * Systems design and integration experience.
 * Sound understanding of secure development and modern engineering standards.
 * Experience of automated testing, software builds and service support.
 * A practical approach to performance, reliability and user needs.
 * Clearance: BPSS required, with a minimum of three years' UK residency.

Previous government, customs or other complex integration programme experience would be beneficial.

## Description

Synergize Consulting is seeking two Java Developers to join a critical central government programme, delivering technology that supports customs compliance, reduces fraud and protects tax revenues.

We welcome applications from experienced developers at different levels. Candidates will be assessed against SFIA 4 or SFIA 5, based on their skills, experience and responsibilities.

The opportunity

You will design, develop and improve software that integrates with existing customs and border systems, helping deliver a reliable, scalable service for traders, marketplaces and carriers.

Your responsibilities will include:

 * Developing secure, maintainable software using Java, JSON, JSLT and Drools.
 * Contributing to systems design, prototyping and integration.
 * Writing clean, reusable, well-tested code using a test-driven approach.
 * Improving development processes and engineering standards.
 * Supporting service availability, capacity and production issue resolution.
 * Working with colleagues to translate user needs into practical technical solutions.
 * Sharing knowledge and mentoring developers where appropriate to your level.