Top Software Engineer Jobs in London

Lead a software engineering team delivering critical infrastructure across complex mission-focused projects. Own team deliverables, contribute throughout the software development lifecycle, collaborate with product, frontend, and QA teams, and mentor junior developers. The role requires backend Java or frontend React expertise, scalable systems development, deployment experience, cloud and containerization familiarity, and strong agile collaboration skills.

Build and maintain on-device LLM software that transforms live neuromonitoring signals into actionable clinical insights. Responsibilities include AI integration, model evaluation, prompting, guardrails, inference optimization, medical device software development, cybersecurity and regulatory compliance, and fleet reliability. The role requires close collaboration with hardware, product, and clinical teams while ensuring safe, reliable performance on constrained hardware.

Develop, maintain and scale high-availability Golang services and APIs for a global payments platform. Design and implement new features, work with event-driven architectures and relational databases, ensure quality via testing and CI/CD, and collaborate across teams to deploy secure, performant systems.

As a Junior Software Engineer, support development and reliability of Fogsphere’s AI platform, focusing on Python, JavaScript, CI/CD, and infrastructure reliability.

Lead technical design and development of complex C# applications. Provide technical leadership, apply best practices (TDD/BDD/DDD), optimize and refactor code, integrate systems, and work with cloud platforms and databases.

Lead development and global rollout of core C++ trading platform components. Implement exchange connectivity (FIX, WebSocket, HTTP), optimize for ultra-low latency (kernel bypass, TLS), build trading algorithms, improve reliability and observability, and collaborate closely with quants and traders to deploy production systems.

Lead design and global rollout of the Core market data and execution platform. Implement high-performance market data ingestion, normalization, distribution, and execution components. Build tools for quants and traders, own component lifecycle (deploy, monitor, profile, optimize), and collaborate closely with engineers, quants, and traders to iterate on platform design.

Design, build, and operate resilient Java and Spring Boot backend services for inventory availability, order promising, and fulfillment. Develop event-driven Kafka integrations, concurrency and consistency controls, caching strategies, observability, and graceful degradation mechanisms. Own services from design through production, optimize performance and reliability, integrate with commerce and enterprise platforms, conduct code reviews, document architecture decisions, and mentor junior engineers.

Own quality strategy, automated testing, and test execution for omnichannel commerce capabilities. Build scalable API, integration, contract, event-driven, and end-to-end test frameworks; manage complex test data; integrate quality gates and regression testing into CI/CD pipelines; define quality metrics; validate order, inventory, fulfillment, returns, and post-purchase workflows; and mentor engineers on quality practices and automation.

Own technical direction and hands-on execution for major products and systems. Design scalable, reliable architectures across backend, frontend, APIs, databases, and infrastructure; write code; lead architecture decisions; solve production problems; improve testing, security, observability, and development practices; and mentor engineers across teams.

Lead technical direction and hands-on execution for major products, systems, and engineering initiatives. Design scalable and reliable backend, frontend, API, database, and infrastructure solutions; write code; make architecture trade-offs; solve production problems; improve testing, security, observability, and development practices; and mentor engineers across teams.

Own technical direction and hands-on execution for major products and systems. Design scalable, reliable architectures across backend, frontend, APIs, databases, and infrastructure; write code; lead architecture decisions; solve production issues; improve engineering quality, testing, security, and observability; and mentor engineers across teams.

Build and scale backend systems for fintech products including bill pay, cards, and fraud detection. Design secure financial integrations, collaborate with frontend, product, and design teams, and deliver features from discovery through production. Improve architecture, performance, code quality, and engineering practices while sharing expertise across the team.

Design, develop, maintain, and review software for critical infrastructure. Contribute to feature design, product roadmaps, Agile task breakdown, CI/CD pipelines, deployments, and customer demonstrations. Provide technical leadership by guiding engineers through delivery and technical challenges while supporting backend or frontend development across cloud, containerization, and database technologies.

Design, architect, and develop customer-facing digital and e-commerce products across web, mobile, social, and in-store channels. Work in Agile Scrum teams using continuous integration and delivery, advise clients on engineering best practices, optimize databases and queries, and contribute to testing and code quality. Mentor and coach team members, promote skills development, and collaborate onsite with clients throughout the software development lifecycle.

As a Senior Software Engineer, you'll shape product features, write backend and frontend code, improve infrastructure, and support integrations in a collaborative environment.

Hands-on principal software engineer responsible for designing and delivering scalable backend services, APIs, frontend components, data pipelines and cloud infrastructure. Own end-to-end delivery, document technical designs, collaborate with clients and cross-functional teams, and operate within an Agile delivery model.

Design, build, and operate Nebius Serverless AI core components (control plane, scheduler, runtime, autoscaler, APIs). Solve cold-start latency, GPU scheduling, multi-tenant isolation, routing. Drive architecture, write design docs, raise engineering standards, run SRE practices, lead incident response, and work with customers and product teams to deliver a scalable, low-latency platform.

Build and scale production inference infrastructure and customer-facing APIs for AssemblyAI’s voice AI models. Partner with researchers and applied engineers to productionize model capabilities, transforming prototypes into reliable, low-latency, well-documented products. Contribute across backend services, SDKs, inference systems, and internal tooling while incorporating customer feedback into product and research direction.

As a Software Engineer - L3 Support, you will resolve complex Ubuntu-related issues, collaborate with teams, and participate in upstream communities to drive bug fixes and improvements.

As a Software Engineer, you will resolve complex customer issues related to Ubuntu and open source software, participate in upstream communities, and develop and review code across multiple layers of the software stack.

Own and evolve the platform security architecture (authN/authZ, secrets, encryption, multi-tenant isolation). Write production code to harden security patterns, run threat models and architecture reviews, set standards, and partner with Security and Platform teams to ship secure platform improvements.

Design and implement platform security features, act as security SME for Core Services, perform threat modeling and secure code reviews, support incident response and vulnerability remediation, and provide secure coding standards and developer training.

Design, build and maintain software and automation for control monitoring, testing, reporting and evidence collection. Integrate with security platforms (SIEM, IAM, EDR), cloud and engineering tools, develop APIs, CLI tools and data pipelines, and translate technical control activity into auditable evidence and reporting to reduce manual audit and assurance effort.

Design, implement, integrate, and deploy autonomy software for defense robotic platforms. Lead architecture and technical decisions, mentor engineers, perform SIL/HIL testing, support live UAV flight tests, interface with sensors and autopilots, and troubleshoot complex integration and real-time edge systems.