Top Java Developer Jobs in Belfast

Lead design, development, and implementation of scalable backend systems in Java. Provide technical leadership, architecture guidance, code reviews, mentor developers, optimize databases (RDBMS and NoSQL), and drive CI/CD and microservices delivery.

Design, develop, and maintain scalable, high-performance backend applications using Java and the Spring ecosystem. Participate across the SDLC, optimize performance, troubleshoot production issues, conduct code reviews, mentor junior developers, and collaborate with product and architecture teams.

Develop Java software solutions, applying object-oriented principles, utilizing cloud technologies like AWS, and collaborating with teams. Lead projects and problem-solve with clients.

Develop and maintain productivity and tooling solutions for Citi developers using Java/SpringBoot microservices on Linux/OpenShift. Build APIs, own SDLC activities, support deployments and CI/CD pipelines, and act as a subject matter expert and consultant to global developer teams.

As a Principal Java Engineer II in the ML Core team, you will build and maintain machine learning components for Elasticsearch, collaborate with engineering teams, and ensure scalable and high-quality code. You'll lead projects from design to implementation while supporting the team and community.

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.

Seeking a Senior Software Engineer with expertise in Kotlin or Java to enhance developer platforms and internal tools at Citi's CTO organization, focusing on server-side engineering and modern databases.

Lead design, develop, and deploy enterprise Java backend and ReactJS front-ends; architect RDBMS and NoSQL solutions; improve CI/CD pipelines; mentor engineers; perform code reviews; troubleshoot full-stack issues; collaborate with product and design; explore integrating AI technologies.

As a Senior Java Developer, you will develop high-quality solutions, mentor juniors, and contribute to technical decisions in a collaborative environment.

The Java Engineer will design and implement scalable solutions, utilizing Java and AWS, while collaborating with cross-functional teams and ensuring agile best practices.

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.

Responsible for training large-language models by reviewing, ranking, and improving AI-generated code. Requires strong software engineering skills.

Evaluate, rank, repair, and refactor AI-generated code to improve correctness, efficiency, and style; provide detailed written feedback for RLHF pipelines; and help maintain the code-evaluation and training workflow remotely.

The Senior Java Developer will support an AI department project, developing Java solutions, collaborating with customers, and documenting technical processes in an Agile environment.

The Senior Java Backend Engineer will lead backend development for a migration project in a complex AWS environment, focusing on automating the actuarial lifecycle in Reinsurance and ensuring alignment with architectural standards.

As a Junior Software Developer, you'll train in Java and Scala, build real applications, and collaborate globally to solve business challenges.

The Full Stack Java Developer will design and implement a proprietary media product, collaborating across teams to develop scalable cloud-native applications with technologies like Java, Node.js, and React.

The Full Stack Java Developer will design and develop scalable cloud-native applications for streaming media, collaborating with cross-functional teams.

As a Senior Product Engineer at Secfix, you will design, build, and maintain backend systems, collaborating with product teams and mentoring junior engineers, while leveraging AI tools for development.

The Technical Architect leads teams to develop high-quality software solutions, manages staff performance, and collaborates on technical design while integrating user journeys and non-functional requirements.

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.

The Staff Software Engineer will own architecture for Java ecosystem infrastructure and build systems, ensuring secure, reproducible build workflows while mentoring peers and enhancing developer tools.

Design, develop, and deliver enterprise-grade full-stack solutions using Java, Node.js, Next.js, React, SQL Server and Couchbase. Build scalable microservices, CI/CD pipelines, containerized deployments, automated tests, and documentation while collaborating across teams and leveraging AI tools to improve code quality.

The role involves improving Elasticsearch's concurrent indexing, maintaining cluster coordination, addressing performance issues, and supporting engineers. Requires strong Java and distributed systems knowledge.

Lead and enable up to two squads to deliver scalable web and mobile digital experiences. Split 50/50 between hands-on engineering and team enablement: design processes, mentor engineers, define sprint goals, estimate effort, reduce technical debt, and align engineering with business objectives while promoting best practices, CI/CD, and automated testing.