Top Backend Developer Jobs in London

Design, implement, and evolve moderate-to-complex backend features, improve system quality, reliability, and performance, mentor engineers, participate in incident response, define backend standards, and integrate agentic AI into production engineering workflows.

Design, develop, test, and maintain high-performance back-end applications and APIs for latency-sensitive, data-intensive trading systems. Collaborate with architects, principal engineers, traders, quants, and business stakeholders throughout the software lifecycle. Contribute to scalable, resilient, cloud-native and event-driven architectures, technical evaluations, automated testing, production support, and continuous improvement initiatives.

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.

Lead and develop a team of engineers focusing on real-time music sharing experiences, collaborating across various technologies and ensuring high-quality user experiences.

Lead multiple engineering teams to build scalable brand advertising and promotions products across backend and front-end systems. Drive engineering strategy, architecture, hiring, mentorship, cross‑functional collaboration, and use of AI/ML for productivity and measurement while ensuring reliability and long‑term technical excellence.

Design, develop, and maintain high-performance, secure Java backend services and APIs. Ensure reliability, scalability, and cost-efficiency across microservices, databases, messaging systems, and capacity planning. Troubleshoot, profile, benchmark, and optimize systems (including ML applications) and collaborate with Kazakhstan stakeholders.

As a Principal Backend Engineer, you will build scalable backend services with Java, design APIs, implement microservices, and work with AWS cloud technologies.

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 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 and manage a cross-functional engineering team to deliver and scale customer-facing products. Own architecture, delivery, reliability, observability, and production outcomes. Coach engineers, run reviews, improve processes and tooling, and drive technical decisions across frontend, backend, APIs, databases, integrations, and infrastructure.

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 manage a cross-functional engineering team to deliver reliable, scalable wealth-management products. Drive architecture, code quality, observability, incident response, and engineering culture while coaching engineers and improving processes to increase delivery speed and reliability.

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 production systems. Own technical architecture, delivery, reliability, and processes. Coach engineers, run reviews, resolve incidents, and drive product outcomes while balancing speed, scalability, and quality.

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.

Build and own backend platform capabilities enabling data scientists, machine learning engineers, and simulation engineers to create, train, and deploy physics-informed models. Collaborate cross-functionally with backend, frontend, design, data science, and simulation teams. Develop scalable, observable production software using Python and Go, including testing, containerization, CI/CD, authentication, event-driven messaging, and Kubernetes-based applications.

Own high-impact backend challenges across services and teams, shape architecture, improve performance, resilience, data integrity, observability, and failure handling. Lead technical decisions, resolve systemic problems, mentor engineers, raise review quality, and partner with product and engineering leadership on long-term technical investments. The role remains hands-on and emphasizes distributed systems, relational databases, concurrency, asynchronous communication, and reliable operation at scale.

Own backend services end to end, from requirements and system design through development, testing, deployment, and production operations. Design scalable, resilient, high-performance systems with strong data integrity, diagnose complex production issues, and make sound technical trade-offs. Collaborate with product and engineering teams, review code, share knowledge, and improve engineering standards. The role requires backend microservices experience, protocol expertise, modern framework fluency, deep relational database knowledge, and experience building highly available systems.

Architect, develop, and operate scalable Java backend services supporting subscription conversion, retention, upsells, and personalized user journeys. Design cloud-native systems, data models, and APIs on Google Cloud Platform; collaborate with product, marketing, growth, and engineering teams; mentor colleagues; and lead complex platform initiatives involving automation, content management, machine learning, and high-volume distributed services.

Join a new London engineering hub to design, implement, and maintain backend services. Own complex backend features end-to-end, drive technical design, ensure high test coverage and scalability, mentor mid-level engineers, and collaborate in a cross-functional agile product team to deliver international-grade products.

Design and deliver end-to-end features for DAP onboarding and repository/background flows. Build autonomous and scheduled agents that act on customer codebases, improve onboarding experience, collaborate on shared interfaces, review code and designs, and contribute to an async-first, distributed team's technical quality and ownership culture.

Design, build, and operate the high-availability event and trigger system that links GitLab and third-party events to AI-powered Duo Flows. Work in GitLab's Rails monolith, scale for high throughput, influence architecture, add trigger types, collaborate cross-functionally, and participate in Tier 2/3 on-call rotations to troubleshoot production issues.

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.

As a Backend/Fullstack Engineer at Hook, you'll design and build product features, manage architecture, review code, and improve processes, focusing on both frontend and backend development using Python and React.