Backend Developer Jobs in Wales, United Kingdom

Turnblock.io backend team builds modular services for a tokenization platform. The Backend Developer (NodeJS) designs, implements, and maintains NodeJS/Express APIs, integrates third‑party RESTful services, and collaborates with frontend and blockchain engineers to deliver scalable products.

Methods is a £100M+ IT Services Consultancy partnering with central government departments and agencies to transform public sector operations in the UK. As a Backend Developer, you will join a digital delivery team to design, develop, and maintain secure, scalable backend services and APIs using TypeScript, AWS, and serverless architectures. You will work collaboratively within an agile multidisciplinary team to deliver robust solutions for public-facing digital services.

Backend Java Developer with deep expertise in Java 17/21, Spring, JDBC, and SQL parsing. Builds deterministic policy engines, data‑governance services, and high‑throughput pipelines for a Data Fabric platform.

Engineering team at Boxbar Tech builds the technology platform that powers automated self‑service drinks across stadiums and events. The role develops Android kiosk features, backend services and payment integrations, and contributes to architecture and reliability improvements.

GitLab's Flow Components team builds the Flow Registry, providing reusable primitives for agentic flows on the GitLab Duo Agent Platform. As a Senior Backend Engineer, you will develop secure, scalable Python backend capabilities using LangChain and LangGraph across the Duo Workflow Service and GitLab monolith, while collaborating across the stack with JavaScript and frontend work to support the Duo Agent Platform client and CLI. This is a full-time, remote role based in the United Kingdom.

GitLab is the intelligent orchestration platform for DevSecOps, enabling organizations to ship better, more secure software faster. As a Staff Backend Engineer in the Developer Experience group, you will work cross-functionally across six globally distributed teams to identify and remove friction affecting internal engineering, split your time between hands-on coding in Ruby and Go, design scalable solutions, and shape engineering culture.

Engineering Team at payabl. builds scalable, high‑performance backend services for fintech and payments platforms. The Senior Backend Python Developer designs and implements Python microservices, integrates third‑party APIs, and drives performance improvements using AWS, Docker, and CI/CD pipelines.

GitLab's Plan: Spec-Driven Development team builds the intent-to-code loop, turning stated intent into refined work items, implementation plans, and verified, mergeable code. As a Senior Backend Engineer, you'll own early-stage backend work across flows, APIs, data models, and evaluation systems using Ruby on Rails, Python, PostgreSQL, and AI gateway services.

As a Backend Developer, you’ll build the engine behind our FollowScores app, turning complex data into real-time updates for millions of football fans. The FollowScores team builds the technology behind our popular football scores app.

As a Backend Developer, you’ll build the engine behind our FollowScores app, turning complex data into real-time updates for millions of football fans. The FollowScores team builds the technology behind our popular football scores app.

As a Backend Developer, you’ll build the engine behind our FollowScores app, turning complex data into real-time updates for millions of football fans. The FollowScores team builds the technology behind our popular football scores app.

As a Backend Developer, you’ll build the engine behind our FollowScores app, turning complex data into real-time updates for millions of football fans. The FollowScores team builds the technology behind our popular football scores app.

Developer Publications team at Apple builds and maintains the backend services that power content creation, distribution, and analytics for Apple platforms. The role designs, implements, and optimizes server-side components, collaborates with cross-functional engineers, and ensures high performance and reliability.

Data, Technology and Analytics team at WPP Media builds the fastest, most connected data platform to bridge marketing strategy to scaled activation. As a Backend Engineer you’ll design and build APIs and services using C#, .NET Core, TypeScript and React, deploy to Azure with Terraform, and collaborate with product, UX and DevOps to deliver secure, performant solutions.

Engineering team at Monzo builds and scales the in‑house banking platform serving millions of customers. The Backend Engineer III designs, implements and maintains resilient Go services using Cassandra, Kafka, Kubernetes and cloud infrastructure, collaborating across product and data teams.

Compliance Team at Cross Border Talents builds a high‑availability payment platform focused on maintainability, performance, and security. The Backend Engineer designs and builds services, integrates APIs, and collaborates with Frontend, Mobile, and product teams to deliver new features.

Attio is building the CRM for agentic revenue, helping ambitious go-to-market teams understand every customer and automate at scale. As a Senior Product Engineer [Backend], you will use TypeScript, Node.js, and GCP to lead projects end-to-end, architect scalable and secure backend systems, design REST API contracts, and represent Product & Engineering values.

Soda is building the first Data & AI performance monitoring platform to help Fortune 500 companies solve data quality bottlenecks. As a Senior Backend + Infrastructure Engineer on the Platform team, you will design and build robust Java services and manage AWS/Kubernetes infrastructure for their multi-tenant SaaS product.

Observability Platform team at Nebius builds a unified ecosystem for logs, metrics, traces and alerting to help engineers operate systems at scale. The Senior Backend Software Engineer will design and scale core services for high‑volume telemetry ingestion, distributed storage and query engines, and enhance AI‑assisted troubleshooting features.

Engineering Teams at Monzo design and build the in‑house banking platform, enabling customers to manage money securely and intuitively. As a Senior Backend Engineer you’ll collaborate in a squad to develop resilient services using Go, Java, Cassandra and Kafka, contributing to core banking, payments and AI‑driven fraud detection.