Top Backend Jobs in Belfast

Build and own backend services, APIs, workflows, and financial infrastructure for an AI neobank. Responsibilities include supporting onboarding, payments, accounts, cards, transfers, rewards, travel, FX, KYC, and risk flows; integrating with financial partners and third-party platforms; and ensuring reliability, security, scalability, observability, and data integrity. The role collaborates with product, frontend, mobile, and AI teams to deliver production systems for millions of users.

As a Senior Backend Engineer at DuckDuckGo, you'll lead backend projects, mentor engineers, and develop AI-enhanced features for the company's privacy-centric product line.

Design, develop, test, and maintain scalable backend applications, services, and APIs using modern engineering practices. Responsibilities include architecture and solution design, unit and integration testing, troubleshooting, code reviews, technical discussions, Agile collaboration, continuous improvement, and mentoring junior engineers. The role emphasizes performance, reliability, scalability, security, maintainability, and translating business requirements into high-quality technical solutions.

Develop backend blockchain functionality for Cardax DEX on the Cardano blockchain. Write and maintain smart contracts in Plutarch and Haskell that define the constraints and conditions for decentralized token exchange without a central entity.

Build and maintain secure, scalable Flow Registry features for GitLab’s agentic platform using Python, LangChain, and LangGraph. Design GraphQL and REST APIs, improve automated testing, optimize PostgreSQL-backed applications, and collaborate across backend, frontend, product, UX, and AI teams. Participate in Tier 2 on-call support, troubleshoot production issues, improve observability, and contribute to responsible AI integration in GitLab’s remote, asynchronous environment.

Design and build backend platform and SDK features for an open-source and cloud product. Responsibilities include database schema design, query optimization, scalable APIs, reliable production systems, security, observability, architecture, and technical roadmap development. The role also involves customer support, code reviews, documentation, open-source participation, and occasional on-call work.

Own significant product areas from customer problem discovery through delivery, measurement, and iteration. Build AI-powered prototypes and production products, use AI coding tools daily, and engage directly with customers and commercial stakeholders. Lead small squads, influence product direction, communicate across technical and business teams, and contribute to an AI-native product engineering culture. The role is fully remote in the UK and focuses on EV energy, virtual power plants, and grid services.

Build and maintain backend AI capabilities for GitLab Duo Chat: design flow components and agentic flows in Python/LangGraph, integrate LLMs and multi-agent orchestration, implement and maintain APIs in the Rails monolith, improve observability and reliability, and participate in on-call rotations and cross-functional collaboration to deliver safe, scalable AI chat features.

Build tooling, workflows, and guidance to make GitLab easier to deploy, validate, and operate across cloud-native and self-managed environments. Evolve deployment guidance, improve production-like ephemeral environments, and maintain consistent deployment artifacts and environment contracts across development through production.

Lead backend work for GitLab's Spec-Driven Development: design and build APIs, data models, evaluation systems, and agent-driven workflows using Ruby on Rails and Python. Ship production services, benchmark LLM workflows, coordinate multi-person projects, mentor engineers, and collaborate with product and design in an all-remote, async environment.

Design, develop, test, and maintain scalable backend services and APIs for Agent Studio. Build orchestration, configuration, integrations, deployment, lifecycle, authentication, authorization, observability, and runtime management capabilities. Collaborate with frontend, AI/ML, product, UX, DevOps, and platform teams to deliver reliable, secure, high-performance services. Troubleshoot complex production issues and contribute to technical designs, code reviews, testing, and continuous engineering improvements.

Designs, develops, and maintains scalable backend services, APIs, and data capabilities for analytics, dashboards, and visualizations. Responsibilities include processing and aggregating structured and unstructured data, optimizing performance, collaborating with frontend, data, UX, product, and DevOps teams, and supporting reliable production deployments. The role also involves technical design, testing, monitoring, troubleshooting, code reviews, and continuous improvement of analytics services.

Lead and manage a cross-functional engineering team to design, build, and operate a high-scale payments app. Drive architecture, delivery, code quality, reliability, observability, and incident response while coaching engineers and improving processes to ship customer-focused products quickly and reliably.

Lead and manage a cross-functional engineering team to deliver reliable, scalable customer-facing products. Drive architecture, code quality, testing, observability, incident response, and engineering processes. Coach and develop engineers, prioritize work with product and design, and ensure fast, high-quality delivery from idea through production.

Lead and grow a high-performing engineering team building scalable, customer-facing products. Own engineering delivery, architecture, code quality, observability, incident response, and engineering culture. Partner with product, design, mobile, backend and AI teams to turn ambiguous problems into production systems while coaching engineers and improving processes to deliver reliable, high-quality outcomes.

Lead technical design and execution of products for an AI-enabled payments app. Hands-on coding, architecture, system design, code review, debugging, production ownership, mentoring engineers, improving dev tooling, and collaborating with product, design and AI teams to ship reliable, scalable systems.

Lead and manage a cross-functional engineering team to design, build, and operate customer-facing products. Own technical architecture, delivery, code quality, reliability, observability, and incident resolution while coaching engineers and improving processes to scale product and engineering outcomes.

Lead and manage a cross-functional engineering team to design, build, and operate scalable, reliable production systems. Own technical architecture, delivery, code quality, observability, incident response, and engineering processes while coaching engineers and driving product outcomes in partnership with product, design, mobile, backend and AI teams.

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.

Lead the Managed Kubernetes Core team while remaining hands-on with backend engineering. Responsibilities include writing and reviewing code, leading technical projects, maintaining technical vision, participating in on-call and incident response, coaching 4–8 engineers, and collaborating on product strategy. The role focuses on Kubernetes control planes, cluster autoscaling, platform integrations, add-ons, GPU infrastructure, and managed cloud services.

Build scalable backend systems for BJAK’s AI Finance Agent, including APIs, workflows, multi-provider insurance integrations, quote comparison and ranking, customer data systems, secure audit trails, cloud infrastructure, CI/CD, observability, and security controls. The role requires reliable handling of timeouts, retries, partial failures, sensitive data, and integrations across markets and partners.

The Backend Software Engineer will manage the lifecycle of short-term projects, perform reliability analysis on applications, and interface with teams to deliver features.

The Backend Software Engineer will develop and maintain backend systems for data processing related to coffee farming, utilizing Python and PostgreSQL. Responsibilities include feature development, problem-solving, and adapting systems to regulatory changes while ensuring system resilience.

Design, build, and scale Node.js backend services for a MERN-based, real-time platform. Improve performance, reliability, and fault tolerance; design APIs and database schemas; collaborate on architecture, code reviews, and operational ownership. Mentor peers, contribute to hiring, and drive engineering standards.

The role involves back-end development using .NET Core and SQL, contributing to Jibble 2.0 API integrations, and collaborating with product and design teams.