Top Software Engineer Jobs in Belfast

Design, build, and maintain backend API and database services for a cloud PBX platform. Drive architecture, performance optimization, debugging, CI/CD and test automation, and collaborate with QA. Mentor peers and raise engineering standards while safely evolving high-load, networked systems.

Build and operate scalable, low-latency APIs, event-driven services, integrations, and web applications supporting membership and loyalty experiences. Integrate and extend Antavo with commerce, CRM, CDP, marketing, and data platforms. Apply distributed-systems, reliability, observability, and security practices; troubleshoot production issues; contribute to reusable engineering assets; and mentor junior engineers.

Leads quality engineering for consumer-facing web and mobile experiences. Designs scalable automation frameworks, develops functional, API, integration, regression, and end-to-end test suites, and integrates quality gates into CI/CD pipelines. Validates accessibility, performance, reliability, and cross-device behavior; investigates defects, analyzes quality metrics, and drives continuous improvement. Collaborates with product and engineering teams, mentors engineers, and applies AI-assisted testing practices.

Design, build, optimize, and support scalable consumer-facing mobile applications across iOS and Android using React Native, TypeScript, and JavaScript. Develop native integrations, reusable components, secure architectures, API integrations, automated testing, CI/CD pipelines, and production monitoring. Collaborate cross-functionally, contribute to releases and Agile delivery, mentor engineers, conduct code reviews, and drive mobile engineering excellence, accessibility, performance, and reliability.

Build and scale Base360.ai: design APIs, services, and cloud-native infrastructure; implement event-driven automations, AI-powered workflows, and integrations (Airbnb, Stripe, Twilio, OpenAI). Own projects end-to-end to automate operations, improve pricing and guest experiences, and enable global scaling.

Associate software developer who will train and join a specialized software team, contributing to design, development, testing, debugging, deployment, and maintenance of software applications. The role involves collaboration across hardware, embedded software, integration, algorithms, and AI/ML teams; completing assigned work; and documenting technical work and learnings.

Build and maintain Clojure-based software to accelerate medical device regulatory approvals. Work cross-functionally to deliver high-quality safety assessments, ship features quickly, and support product growth. Remote-first, collaborative environment with occasional in-person weeks in London.

Build and operate Grafana Labs' bare-metal platform: provision storage, networking, and Kubernetes clusters; manage cluster networking, scheduling, autoscaling; maintain Crossplane compositions and Terraform modules; collaborate with application teams and participate in on-call rotation to ensure reliable, scalable platform operations.

Responsible for designing and implementing authentication features in Go and TypeScript, enhancing Auth architecture, and collaborating with teams to improve user experience.

Join Uncountable's Implementations Engineering team to build software that integrates R&D lab instruments with their platform, working closely with customers and developing automated data pipelines.

Design, maintain, and scale backend services and APIs connecting Phantom Cash to blockchains. Build reliable event-driven systems with REST APIs, distributed-system patterns, retries, idempotency, and data consistency. Collaborate across teams, document decisions, mentor engineers, and improve engineering standards. The role also involves blockchain integrations, operational ownership, observability, and delivering dependable financial products in a remote crypto environment.

Freelance software developer responsible for designing, developing, testing, and maintaining high-performance applications. Collaborate with cross-functional teams to deliver innovative, client-focused solutions on a remote, on-demand platform.

Join ROOST's Coop project to design, implement, test, document, and release trust-and-safety features. Work across backend APIs, GraphQL, databases, and UI to improve reviewer workflows, detection integrations, and reporting. Lead code quality, security practices, community contribution reviews, and stakeholder coordination while engaging with users and the open source community.

Join the ROOST Osprey team to design, implement, test, and maintain a high-performance, real-time safety rules engine. Work includes building data/event pipelines, scaling and containerizing services, integrating with Kafka and gRPC, reviewing community contributions, maintaining code quality and security, and engaging with users and open source contributors to prioritize and deliver features.

Build a decentralized, serverless P2P search stack using Node.js. Implement and evaluate distributed indexing, DHTs, CRDTs, and networking (NAT traversal, encryption, multiplexing). Optimize protocols and high-concurrency networking code and work with the Holepunch stack components like hyperdht and hyperswarm.

As a Backend Software Engineer, you'll develop and maintain REST APIs using Django, manage cloud infrastructure, and oversee CI/CD pipelines to support consumer fintech applications.

As a Software Engineer, you will build and maintain financial platforms and applications that help homeowners track and manage their expenses, collaborate with the engineering team, and utilize AI for data insights.

As a Software Engineering Intern, you will contribute to building features for user-facing products, APIs, and scalable services for machine learning. Responsibilities include crafting code, designing data pipelines, implementing tools, and enhancing technical documentation.

Lead technical teams to design, build, test, and maintain modern, scalable, secure software. Provide technical ownership for product architecture, estimation, planning and requirements. Coach and develop junior staff, drive CI/CD practices, troubleshoot live applications, and liaise with customers as the teams technical leader.

Build and operate stateful streaming pipelines and Go services that process usage events into accurate, near-real-time billing data. Responsibilities include ingestion, validation, enrichment, pricing, storage integration, usage APIs, billing exports, failure recovery, idempotency, exactly-once processing, reconciliation, scalability, observability, and deployment ownership.

Design and build distributed backend services for the cloud monetization platform, focusing on correctness, consistency, scalable microservices, distributed transactions, and reliable asynchronous workflows. Influence system architecture, own service implementations, and collaborate across teams to support billing, reservations, payments, and revenue flows.

Build and maintain integrations for North's agentic platform, own the end-to-end integration pipeline, create evals and tests to ensure reliability, tune tool descriptions, and help other engineers add and maintain integrations while using AI responsibly to improve performance and quality.

The Software Engineer will design, develop, and support the MEMX Trading system software, focusing on production support during US evening hours.

Build and maintain internal and public-facing APIs and services powering the Web App and developer experience. Develop API functionality, Admin API systems, WebSocket and REST behavior, and usage and billing integrations with Stripe. Investigate production issues and security vulnerabilities, write and review tested code, make technical decisions, and collaborate across engineering, Product, and Design teams.

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.