Top Software Engineer Jobs in Belfast

Build and evolve Elastic’s MCP server, agent skills platform, developer tooling, CLI enhancements, and third-party AI ecosystem integrations. Develop and support libraries and integrations primarily in Go, with Rust and other languages. Establish evaluation-based correctness standards, collaborate with product teams and external partners, contribute product thinking, and improve developer experience across a globally distributed team.

Lead design and development of Windows desktop applications. Ensure performance, maintainability, and accessibility, while driving feature lifecycle and collaborating cross-functionally.

We are seeking a collaborative Backend Engineer with Java expertise to design, build, and maintain backend services, focusing on operational excellence and system reliability. Responsibilities include architecture, automation, and supporting production environments in a multi-cloud setting.

Design, implement, and maintain scalable backend systems supporting Alpaca’s financial ledger and brokerage infrastructure. Own high-visibility features from design through deployment, collaborate with finance, operations, product, and engineering stakeholders, and improve system health. Build performant, reliable, maintainable services using modern distributed systems technologies while ensuring the ledger remains a correct source of truth for account transactions, reporting, and compliance.

Designs, develops, integrates, tests, and maintains production embedded Linux software for vehicle systems. Responsibilities include modern C/C++ and Qt/QML development, Yocto platform maintenance, Python automation, CI/CD, automated testing, debugging across hardware and software boundaries, release management, architecture, documentation, and production support. The role also provides technical leadership and mentorship while collaborating with multidisciplinary engineering, manufacturing, cybersecurity, and supplier teams.

Architects and develops enterprise Change Data Capture and data integration software across mainframe and distributed platforms. Processes transaction logs, analyzes database internals and binary formats, reverse engineers legacy systems, and resolves performance, reliability, compatibility, and data-integrity issues. Provides technical leadership, mentors engineers, collaborates on customer escalations, and supports critical production incidents and releases.

Lead technical strategy and architecture for personalization, search, and recommendation systems. Deliver scalable ML-powered features, mentor senior engineers, and improve engineering quality across cross-functional teams.

As a Principal Engineer at M&S, you'll drive technical strategy, influence architecture, and mentor engineers while delivering on personalization, search, and machine learning features in collaboration with cross-functional teams.

The Senior Software Engineer will lead the development of backend systems for payment processing, collaborating with teams, setting goals, and fostering quality and ownership in code development.

Lead design and implementation of scalable AI-centric systems for offensive security, develop agentic AI capabilities (LLMs, RAG), own feature lifecycle to production, mentor engineers, run design reviews, and integrate AI into microservice architectures with cloud, container, and messaging technologies.

Build and ship native Android features in Kotlin for an AI-enabled neobank. Design clean mobile flows for payments, insurance and financial services, integrate backend APIs, improve performance and reliability, use analytics and on-device ML (TensorFlow Lite) to enhance user journeys, and collaborate with product and design.

Design, implement, and maintain full-stack web features for a dairy farm management system. Own development lifecycle, ensure quality and reliability, support customers and technicians, and collaborate across cross-functional teams.

Lead quality engineering across the software lifecycle by designing scalable automated testing frameworks, developing API and UI automation, improving CI/CD testing infrastructure, researching AI-enabled testing approaches, defining test strategies and metrics, and mentoring engineers. The role requires strong programming, cloud, database, automation, and cross-functional collaboration skills in a hybrid Belfast fintech SaaS environment.

Build and maintain scalable, reliable agentic AI systems for biomedical research, integrating LLMs, tool-calling, and data platforms. Drive technical decisions, optimize analytical workflows, deploy agents on the data platform, mentor teammates, and participate in on-call rotation to ensure performance, security, and continuous improvement.

Analyze and optimize ClickHouse database performance, develop performance tests, support engineering teams, collaborate with core teams, and engage with the open-source community.

Lead the design and development of complex Rails features, mentor junior engineers, define technical direction, and ensure high-quality code while collaborating with stakeholders.

Design, build, and operate resilient Java and Spring Boot backend services for inventory availability, order promising, and fulfillment. Develop event-driven Kafka integrations, concurrency and consistency controls, caching strategies, observability, and graceful degradation mechanisms. Own services from design through production, optimize performance and reliability, integrate with commerce and enterprise platforms, conduct code reviews, document architecture decisions, and mentor junior engineers.

Own quality strategy, automated testing, and test execution for omnichannel commerce capabilities. Build scalable API, integration, contract, event-driven, and end-to-end test frameworks; manage complex test data; integrate quality gates and regression testing into CI/CD pipelines; define quality metrics; validate order, inventory, fulfillment, returns, and post-purchase workflows; and mentor engineers on quality practices and automation.

Own technical direction and hands-on execution for major products and systems. Design scalable, reliable architectures across backend, frontend, APIs, databases, and infrastructure; write code; lead architecture decisions; solve production problems; improve testing, security, observability, and development practices; and mentor engineers across teams.

Own technical direction and hands-on execution for major products and systems. Design scalable, reliable architectures across backend, frontend, APIs, databases, and infrastructure; write code; lead architecture decisions; solve production issues; improve engineering quality, testing, security, and observability; and mentor engineers across teams.

Lead technical direction and hands-on execution for major products, systems, and engineering initiatives. Design scalable and reliable backend, frontend, API, database, and infrastructure solutions; write code; make architecture trade-offs; solve production problems; improve testing, security, observability, and development practices; and mentor engineers across teams.

Build and scale production inference infrastructure and customer-facing APIs for AssemblyAI’s voice AI models. Partner with researchers and applied engineers to productionize model capabilities, transforming prototypes into reliable, low-latency, well-documented products. Contribute across backend services, SDKs, inference systems, and internal tooling while incorporating customer feedback into product and research direction.

Develop and maintain the backend ecosystem for the Alta Video Management System, focusing on cloud-based distributed systems and coding quality.

Lead the design and implementation of core authentication infrastructure at Phantom, focusing on secure authentication systems, secrets management, and API integrations.

As a Software Engineer, you'll develop trading APIs and systems, enhance user experiences, and lead initiatives for blockchain support and new products.