Top Java Developer Jobs in Belfast

As a Senior Software Engineer, you will develop and maintain the equity derivatives reference data platform, ensuring data quality and governance while mentoring junior developers.

Citi seeks a Senior Software Engineer (Java) to design and develop complex, high-performance systems for fixed income trade processing, utilizing Java and Spring technologies.

Senior full‑stack engineer responsible for designing and delivering scalable, cloud‑native applications using Java or Python. Solve complex business problems, set coding standards, mentor mid‑level developers, integrate Gen‑AI capabilities (LLMs, prompt engineering, vector search) and third‑party Gen‑AI APIs, and collaborate with management to deploy new products while ensuring compliance and risk controls.

The role involves writing high-quality back-end code in Java or Kotlin, contributing to architectural decisions, and automating SDLC processes. You will lead a small team, apply AI in projects, and ensure clear communication across distributed teams.

Design, develop, maintain, and enhance SecureFlag’s backend Java platform using microservices. Build automated tests and CI pipelines, troubleshoot performance and production issues, implement new functionality, and collaborate closely with the engineering team. The role requires independently improving scalable Java applications, diagnosing Hibernate bottlenecks, and supporting secure coding education technology in a remote, fast-paced environment.

Design, build, test, and maintain Java 17+ microservices for a banking modernization program. Develop REST APIs and messaging integrations, containerize and deploy services through CI/CD, integrate relational and NoSQL databases, and address performance, resilience, security, and observability. Participate in Agile delivery, solution design, code reviews, testing, and production releases while collaborating with architects, analysts, testers, and product owners.

The Staff Software Engineer will design and manage end-to-end data pipelines, ensuring data quality and governance while collaborating across Java and Python systems, including event schema design and AI tooling.

Hands-on software engineer working in a squad to build resilient digital solutions. Collaborate with stakeholders to deliver customer-facing features, follow best practices and standards, reduce technical debt, mentor peers, support DevOps responsibilities, contribute to sprint goals, and drive continuous technical improvement.

As a Senior Java Developer, you'll lead software development using Java and AWS, collaborating in an Agile team, adhering to best practices, and creating maintainable solutions.

Develop, implement, and support enterprise software using Java/Spring Boot and Angular. Collaborate with product and agile teams to design, code, test, review and deploy microservices and APIs, provide production support, document artifacts, and ensure scalability, performance and adherence to architecture and best practices.

Design, build, and optimize low-latency, high-throughput Java microservices and REST APIs for payments. Deploy and scale services on OpenShift/Kubernetes and AWS, integrate with MongoDB/other datastores, improve performance and observability, mentor engineers, and drive architectural best practices.

Develop, maintain, and support a Java-based global transaction reference platform. Build APIs, messaging integrations, and distributed systems; troubleshoot production issues; improve architecture and SDLC with containers, CI/CD, and AI-assisted tooling; collaborate across teams and provide documentation to meet performance and scalability targets.

Design, implement and evolve core components of a Java-based distributed runtime: cluster services, distributed data structures and execution engines. Work on partitioning, replication, coordination and recovery, write reliable low-latency production code, contribute to architecture, reviews and mentoring.

Develop and enhance the Global Market Data low-latency platform for Equities: design microservices, implement new functionality, support production systems, coordinate exchange changes, and troubleshoot with traders and support teams.

Design, build, and maintain scalable, highly available backend services in Java. Own backend architecture, optimize performance, develop APIs and integrations, support production, conduct code reviews, and contribute to AI engineering tools and infrastructure.

Administer, monitor, and support Java applications and Genesys Cloud. Provide production troubleshooting, minor bug fixes and enhancements, and act as primary POC for Java apps. Develop/support microservices using Java and Spring Boot, perform analysis of system behavior, and apply problem-solving and diagnostics to maintain service quality.

As a Senior Software Engineer, you'll maintain critical data framework integrations, ensuring performance and reliability while collaborating with the community, affecting real-time analytics and observability systems.