Top Java Developer Jobs in Belfast

Design, develop, and maintain high-performance, secure Java backend services and APIs. Ensure reliability, scalability, and cost-efficiency across microservices, databases, messaging systems, and capacity planning. Troubleshoot, profile, benchmark, and optimize systems (including ML applications) and collaborate with Kazakhstan stakeholders.

Seeking a Software Engineer (Java) for developing complex, high-volume trade processing systems in the Fixed Income domain, ensuring quality and efficiency.

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.

Develop and maintain scalable backend services and integrations using Java and Spring Boot. Design and consume REST APIs, work with PostgreSQL and Flyway, build event-driven solutions on AWS, containerise with Docker/Kubernetes, write automated tests, monitor with Datadog, and support production systems while collaborating across product and platform teams.

Design, build, and maintain efficient, reusable Java backend systems; translate business requirements into applications; optimize performance and stability; review and test code for quality and security; identify and fix bottlenecks and bugs; maintain code quality and system responsiveness.

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.

Design, develop and execute automated tests within a BDD framework (Cucumber). Build API automation, create test plans/cases, perform SQL validation, log and track defects, support CI/CD pipelines, and collaborate with dev and production support to prevent production issues.

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.

Lead UI-focused full stack development for global equities finance platform. Provide technical direction, design and code review, resolve complex problems, mentor developers, and deliver solutions using agile practices while ensuring compliance, resiliency, and stakeholder alignment across global teams.

The role involves developing software solutions for credit risk management, applying cloud principles, and enhancing business processes while ensuring compliance standards.

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.

As a Senior Software Engineer, you'll develop high-quality software solutions, mentor junior members, apply best practices in design and build, and contribute to technical decisions in a collaborative environment.

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.

Design, develop, and optimize high-performance Java backend systems. Contribute to architecture, implement core modules, troubleshoot production issues, perform code reviews, and improve scalability, availability, and reliability of distributed financial or blockchain systems.

Develop and enhance the ASPEN asset servicing application using Java, Angular, and Oracle. Analyze, test, debug, and secure applications, work in an agile global team, identify system improvements, and implement solutions under deadlines.

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.

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.