Top Backend Jobs in Belfast

Develop and maintain scalable .NET backend services, REST and GraphQL APIs, and microservices. Design SQL Server schemas, optimize queries, implement Entity Framework Core data access, and build secure authentication flows. Collaborate in Agile teams with product, frontend, and QA stakeholders. Write automated tests, apply Clean Architecture and DDD, resolve performance and production issues, maintain API documentation, and support Azure DevOps CI/CD, Docker, monitoring, and structured logging.

Develop and maintain scalable Atlassian cloud products using Kotlin, Java, and server-side technologies. Responsibilities include writing clean, testable code, creating unit and integration tests, conducting code reviews, designing APIs, optimizing performance, and collaborating with product, design, QA, and technical writing teams. The role requires building distributed systems using Kubernetes and AWS, working with SQL and NoSQL databases, and solving complex customer and product challenges autonomously in a remote environment.

Architect and develop high-load backend systems in Elixir, design scalable distributed solutions, and improve ticketing and event-management platforms. Lead technical discussions, translate requirements into specifications, mentor engineers, conduct code reviews, and promote testing, documentation, maintainability, and production ownership. Optimize PostgreSQL and Redis performance, integrate third-party services, understand Linux internals, and address system bottlenecks and traffic spikes.

Leads high-impact backend and financial operations projects involving payments, transactions, middleware, GraphQL schemas, APIs, and data models. Provides staff-level technical leadership, drives architectural decisions, partners cross-functionally with Product and Design, and improves engineering standards such as testing, code review, documentation, and SDLC practices. Works hands-on across project delivery while shaping company-wide engineering culture and technical direction.

Design, implement, review, and validate production-grade Rust backend systems for AI training projects. Responsibilities include API development, persistence, asynchronous and concurrent processing, performance optimization, reliability testing, debugging, architecture assessment, and creating reproducible workspaces and containerized test environments. The role requires clear technical documentation, evaluation of edge cases and failure scenarios, and consistent delivery of approximately 15 hours of weekly project work.

Build and operate scalable AWS cloud infrastructure centered on Amazon EKS, networking, infrastructure-as-code, and self-hosted services. Automate shard deployments, implement Terraform guardrails and secure ingress, support multi-region growth, and meet reliability, disaster recovery, compliance, and security requirements. Partner cross-functionally, troubleshoot application and infrastructure issues, participate in on-call and incident response, and use AI tools to improve engineering workflows.

Lead hands-on backend engineering using Java, Spring Boot, REST APIs, and Kafka-based services. Own technical direction, delivery, architecture, testing, integrations, and DevOps practices while mentoring engineers and championing AI-assisted development. Manage workstream risks, timelines, bottlenecks, client communication, estimation, and delivery planning in a fast-paced consultancy environment.

Build, maintain, and scale e-commerce backend services using Python and Django. Develop REST APIs and features for catalogs, inventory, carts, checkout, orders, payments, and customer accounts. Integrate external services, optimize databases and performance, implement security and access controls, write tested code, resolve production issues, and contribute to architecture, code reviews, deployment, and CI/CD.

Lead the technical direction and architecture of the Foundations platform team, owning authentication, authorization, SSO, secrets management, tenancy, and core platform services. Design APIs, drive services through launch, make technical decisions, establish engineering standards, and mentor engineers without formal management authority. Partner with engineering and product leaders to align execution with priorities.

Senior backend engineer responsible for designing, coding, and operating highly available distributed identity systems for Affirm’s international markets. The role includes owning quarterly goals, delivering scalable features in Kotlin and Python, collaborating across product and engineering teams, improving code and design standards, monitoring system availability, resolving production issues, mentoring engineers, and supporting technical planning and hiring.

Design, build, and operate high-throughput backend services, APIs, real-time streaming applications, and data pipelines. The role includes using Kafka, Flink, and cloud infrastructure; monitoring system health and data freshness; investigating incidents; improving observability, testing, CI/CD, and maintainability; and collaborating with product and platform teams to deliver scalable maritime intelligence solutions.

Design, build and operate backend services in AWS for a multi-service hospitality platform. Implement new features, payment and EPOS integrations, improve performance, monitoring and deployment automation using TypeScript/Node.js and databases like Mongo Atlas, Postgres RDS or DynamoDB. Collaborate in a UK development team and automate infrastructure, CI/CD and QA.

Build and operate backend safety infrastructure, including automated moderation, abuse detection, AI guardrails, APIs, internal tools, and production services. Integrate machine-learning models, monitor system reliability, respond to emerging threats, and translate product, legal, and policy requirements into scalable technical solutions. Collaborate across engineering, investigations, product, legal, and safety policy teams while shaping the architecture and evolution of ElevenLabs’ safety systems.

Own an AI-agent-driven backend engineering lifecycle for beqom’s multi-tenant data platform. Define agent-executable specifications, build agent orchestration and MCP infrastructure, and create behavioral verification, evaluation, sandboxing, and governance systems. Direct AI agents delivering ingestion, schema, snapshots, calculated fields, and export services. Assess generated solutions for scalability, performance, reliability, and security; diagnose production issues; and collaborate with product, analytics, support, and engineering teams.

Build and operate backend services and streaming data pipelines that ingest sensor, rail, and waterway data into Kpler’s commodities intelligence platform. Responsibilities include developing Python and FastAPI services, maintaining Kafka and Airflow pipelines, validating time-series data, deploying cloud services, monitoring systems, improving CI/CD, supporting customer-facing applications, and participating in on-call operations.

The Full-Stack Engineer will enhance backend functionality, collaborate with teams, and maintain platform performance and security, requiring expertise in Python.

Build backend data frameworks and tooling that keep GitLab’s datastores scalable, healthy, and safe across SaaS and self-managed deployments. Develop retention and lifecycle controls, schema-change guardrails, bulk data removal tools, SQL traffic replay, and background operations frameworks. Collaborate across engineering and product teams, review database changes, improve performance and migration safety, document best practices, and participate in a tier 2 database on-call rotation.

Build and optimize high-performance Elixir/Phoenix backend systems with PostgreSQL at scale. Design efficient schemas, queries, indexes, batching strategies, migrations, and concurrency patterns. Diagnose database bottlenecks, support large document volumes, and improve reliability across cloud and self-hosted deployments. Contribute to AI-assisted engineering workflows, platform architecture, tooling, and customer success while collaborating with a remote-first team.

Design, build, operate, and maintain scalable alerting backend systems. Drive features end-to-end, contribute to open-source, participate in on-call rotations, mentor teammates, and collaborate remotely to improve reliability, performance, and alert evaluation at scale.

Set long-term technical strategy for backend identity systems, lead major distributed-system initiatives, ensure operational availability, establish engineering quality standards, collaborate cross-functionally, and mentor engineers. Build and launch highly available systems supporting international expansion, KYC verification, identity data management, decisioning, regulatory compliance, and global risk models.

Build and operate high-traffic backend services for Universal Wallet, supporting fiat and stablecoin deposits, withdrawals, balances, integrations, and settlement. Develop across Python and Kotlin/Java stacks, design APIs and event-driven systems, improve architecture and observability, review code, and participate in on-call production support. Collaborate asynchronously across teams, influence technical decisions, and deliver reliable financial infrastructure.

Build and operate high-performance backend systems and distributed services using Elixir and Phoenix. Design declarative infrastructure with Terraform, Terramate, FluxCD, Kubernetes, and Helm; manage AWS cloud workloads, cluster upgrades, GitOps workflows, observability, and databases. Collaborate with a remote engineering team on architecture, product development, debugging, reliability, and customer success.

Leads backend architecture and streaming services for high-volume maritime tracking and trade data. Builds Python and PHP microservices, Kafka pipelines, and PostgreSQL and ClickHouse data systems. Owns production reliability, observability, CI/CD, and containerized deployments while collaborating with product, platform, and client-facing teams. Mentors engineers, drives modernization, and establishes technical standards.

Lead cross-functional Developer Experience initiatives across six teams, contributing hands-on backend code in Ruby and Go. Improve testing reliability, test coverage, CI/CD pipelines, logging standards, and development environments. Partner with engineering, platform, product, and infrastructure teams to identify friction, remove systemic bottlenecks, shape the Developer Experience Platform strategy, and foster continuous engineering improvement.

Own technical direction and execution for major products and systems. Design scalable backend, frontend, API, database, and infrastructure solutions; write code; prototype; review code; debug production issues; make architecture trade-offs; convert ambiguous problems into execution plans; improve engineering quality; lead critical initiatives; and mentor engineers.