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# Senior Java Developer - o/s IR35 - Hybrid - 18 month cx

- **Company:** iO Associates
- **Location:** London, UK
- **Experience:** Expert
- **Contract:** Temporary contract
- **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Agile Methodology, Microsoft Azure, Cloud Computing, Continuous Integration, Couchbase Servers, DevOps, Distributed Systems, Github, PostgreSQL, NoSQL, Rxjava, Software Engineering, Java Application Server, Test-Driven Development (TDD), Spring-boot, Software Troubleshooting, Marshalling, Event Driven Architecture, Kubernetes, Apache Kafka, Api Design, Splunk, New Relic (SaaS), Appdynamics, Docker, Microservices
- **Published:** September 12, 2026
- **Apply:** https://www.totaljobs.com/job/senior-java-developer/io-associates-job107975175

## About the Role

* Strong commercial experience developing Java applications
 * Hands-on experience with Spring Boot and microservices
 * Experience building scalable, distributed and highly reliable systems
 * Strong API development and integration experience
 * Experience with Kafka/event-driven architecture
 * Good understanding of PostgreSQL and/or NoSQL databases
 * Experience with CI/CD and DevOps
 * Agile product development experience
 * Strong understanding of software design, testing and TDD
 * Experience working with cloud technologies, ideally Azure

## Description

a major retailer is urgently seeking Senior Java Developer to woprk in a globally distributed engineering team building a next-generation, scalable fulfilment platform supporting both manual and automated/robotic warehouse operations.

The platform powers customer order fulfilment across multiple geographies and product categories, using real-time technology to optimise picking, marshalling, dispatch and warehouse workflows.

This is a greenfield development project, offering the opportunity to work on highly scalable, mission-critical systems and have a direct impact on operational efficiency and customer experience.

What You'll Do

 * Design and develop high-performance Java applications and microservices
 * Build and integrate APIs and distributed systems
 * Develop scalable, resilient and highly available solutions
 * Work across the full software lifecycle, from design through to production
 * Troubleshoot complex technical issues in a mission-critical environment
 * Work closely with data, hardware and operations teams
 * Contribute to CI/CD, automation and DevOps practices
 * Support and mentor less experienced engineers

Tech Stack

Core: Java, Spring Boot, RxJava
Data & Eventing: Kafka, PostgreSQL, Couchbase
Cloud & DevOps: Azure, Docker, Kubernetes, Azure DevOps / GitHub Actions
Monitoring: Splunk, AppDynamics, New Relic