Top Software Engineer Jobs in Belfast

Build and maintain Ruby on Rails backend features for vulnerability management, including security dashboards, reports, and ingestion pipelines. Improve system performance, reliability, and scalability; collaborate across backend, frontend, product, design, and security teams; review code; address technical debt; and participate in on-call rotations. The role requires relational database experience, distributed-team collaboration, technical problem-solving, and contributions across the stack when needed.

Join the International Accelerator full-stack team to design, build, and operate Direct-to-Consumer products across international markets. Break projects into tasks, collaborate with PM/design/analytics, build and monitor APIs and web apps, support on-call and availability, participate in hiring and team growth, and write clear, well-tested, maintainable code.

The Software Engineer will design, develop, and maintain backend services and APIs for Speechify, ensuring they meet business and scalability requirements. The role involves collaboration on B2B solutions and aligning backend architecture with product strategy.

Design, develop, test, deploy, maintain, and enhance enterprise IoT software products. Contribute to the architecture of a global multi-cloud, multi-region platform, enforce SDLC and DevSecOps practices, support CI/CD pipelines, conduct technology research and proofs of concept, and provide technical leadership, mentoring, and direction. Collaborate with partner teams to deliver scalable, secure, reliable systems that enable real-time IoT monitoring and data-driven decision-making.

Build and maintain reliable, high-performance frontend features for an AI assistant. Responsibilities include developing responsive interfaces, managing application state, maintaining code quality, conducting code reviews, writing automated tests, debugging complex applications, and optimizing rendering and memory performance. The role involves collaborating remotely with a globally distributed team and may include desktop, cross-platform, real-time communication, P2P, and decentralized technology development.

As a Software Engineer II, you will build and maintain features on Stora's Rails-based platform, improve app stability, and collaborate with a small team on various domains.

Develop and enhance web-based digital farm management solutions for the dairy industry. The role involves designing maintainable software, contributing across the full development lifecycle, supporting users and technicians, testing and optimizing applications, and collaborating with developers, testers, and product managers. The position uses Java, Spring, TypeScript, Angular, PostgreSQL, Docker, and Azure-based development tools in a hybrid Belfast environment, with occasional international travel.

Build and architect Base360.ai: design and launch booking, pricing, payments, operations, and AI-powered automation. Integrate platforms (Airbnb, Stripe, Twilio, OpenAI), scale systems internationally, and embed AI workflows to automate operations and optimize revenue.

As a Software Engineer Intern, you'll develop innovative solutions, gain exposure to the software development lifecycle, and collaborate in an Agile environment at Visa.

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.

Design, prototype, and maintain high-performance systems software with emphasis on firmware, device drivers, hardware interfaces, and real-time communication (WebRTC/WebSockets/REST). Debug and resolve low-level issues, collaborate with cross-functional teams, participate in code reviews, ensure security and compliance, and contribute to continuous improvement and POCs.

Build and maintain scalable test automation frameworks and QAOps infrastructure for UI, API, backend, and end-to-end testing across multi-cloud environments. Integrate automation into CI/CD pipelines, analyze test and production telemetry to identify risks, support release validation and QA sign-off, and drive quality engineering best practices across distributed teams.

Join the Middleware team to build and maintain microservices powering real-time message delivery, tenant lifecycle management, and search. Develop features, scale services, implement automation with GitOps/CI-CD, and collaborate with SRE and senior engineers on code reviews, documentation, and operational tooling.

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.

Build and own marketing-focused web projects, including landing pages, campaign pages, and website updates. Ship production-quality front-end code, improve technical SEO, and ensure performance, accessibility, UX, and UI quality. Partner with Marketing, designers, developers, and external agencies to scope, coordinate, and deliver projects. Work primarily with Angular 13 while adopting modern frameworks and AI-assisted coding practices.

Develop, customise, and support InterSystems TrakCare healthcare applications using Caché, MUMPS, and Cache ObjectScript. Configure Ensemble interfaces, integrate REST APIs, build SQL reports and automation, optimise queries, conduct code reviews, and resolve defects. Support UAT, go-lives, deployments, and post-implementation stabilisation across hospital units while collaborating with clinical, administrative, and technical stakeholders.

As a Senior Software Engineer, you will enhance the REDAPL platform, leading initiatives in data ingestion, processing, and supporting infrastructure-related projects while mentoring other engineers.

Design, develop, test and deploy back-end services and APIs (.NET C#) for a cloud-native distributed platform. Implement IaC with AWS CDK, collaborate in Agile teams, ensure quality via unit/automated testing, troubleshoot issues, document systems, and drive platform modernisation.

The Software Engineer will enhance data collection and ingestion pipelines for AI model training, collaborating on dataset roadmaps and managing cloud infrastructure.

Lead the design, development, deployment, and maintenance of scalable cloud-native platform capabilities for Walmart Connect’s sponsored search ad server. Build infrastructure, tooling, AI/ML frameworks, and distributed systems; conduct design reviews; drive software lifecycle activities; mentor engineers; influence architecture and technical decisions; and collaborate across teams to translate complex business needs into reliable, data-driven solutions.

Develop and maintain Windows endpoint security software, including product features, testing, releases, fixes, and improvements. Participate in code reviews, Agile ceremonies, security reviews, troubleshooting, and production support while collaborating with senior engineers. The role requires strong computer science fundamentals, problem-solving, communication, ownership, and a relevant degree or equivalent experience. C++, Python, Windows development, driver development, and cybersecurity interest are desirable.

Develop and maintain full-stack web applications using C#, .NET (including .NET 8), Blazor and Angular 15. Build APIs, integrate databases (MySQL, SQL Server, MongoDB), write tests, perform code reviews, optimize queries, document systems, and collaborate in Agile teams to deliver high-quality solutions.

Senior backend engineer role building scalable, resilient Go-based backend services and APIs for cloud environments (AWS/Azure/GCP). Work with containers, Docker, Kubernetes, TDD, and performance optimisation while collaborating with client teams in a remote-first consultancy.

Responsible for building and maintaining Android applications with AI features. Focus on performance, UX design, and collaboration with backend and ML engineers.

As an iOS Developer, you will build and maintain AI-powered iOS applications focusing on performance, reliability, and user trust. Collaborate with engineers to integrate AI features, design UX patterns, and optimize app performance.