Top Software Engineer Jobs in London

Lead design, develop, test, and deploy production-grade C++ software for autonomy and defence customers. Integrate customer software, mentor junior engineers, and travel to customer sites and offices.

Lead the architecture and hands-on development of reliable AI-powered email applications across backend, mobile, and desktop platforms. Design orchestration, state management, tool use, retries, fallbacks, and failure handling for long-running workflows. Build production APIs, improve observability and reliability, make trade-offs involving latency, cost, security, and user experience, and lead a small senior engineering team through technical reviews, mentorship, and execution.

Leads application engineering for an AI-powered email product across backend, mobile, and desktop platforms. Designs reliable AI workflows involving orchestration, state, tool use, retries, fallbacks, and failure handling. Builds APIs connecting AI capabilities to product experiences, makes architectural trade-offs, establishes observability and operational excellence, and leads a small senior engineering team through mentorship, design reviews, and code reviews. Partners with ML leadership to deliver scalable, reliable, and maintainable production systems.

Lead application engineering for an AI-powered email product across backend, mobile, and desktop platforms. Design reliable AI workflows involving orchestration, state, tool use, retries, fallbacks, and failure handling. Build APIs connecting AI systems to product experiences, make architecture and scalability decisions, mentor senior engineers, and establish strong observability, monitoring, testing, security, and operational practices. Partner with ML leadership to ship fast, reliable, maintainable product experiences.

Lead technical direction for an analytics and observability platform capturing product event data. Solve multi-system scaling problems, enable self-service and AI tools, improve tooling and processes, mentor engineers, and partner with product, trading, and business teams to expose reliable data and insights company-wide.

Build and operate production systems for Coder’s agentic development experience. Develop Go-based backend systems, contribute to React and TypeScript applications, improve agent execution and context management, and create reliable integrations across models, tools, workspaces, and developer infrastructure. Own projects through rollout, enhance system reliability and performance, participate in technical reviews, and collaborate with Product and Design to deliver useful AI-powered developer experiences.

Architect, develop, integrate, test, debug, and optimize embedded software for diverse hardware platforms using RTOS, bare-metal, Zephyr, and Linux environments. Lead software architecture, system validation, test automation, and multi-threaded application development while collaborating with hardware and software teams. Define test strategies, analyze defects, document designs, conduct code reviews, mentor engineers, optimize performance and power usage, and contribute to open-source projects.

As a Senior Software Engineer at KoBold, you'll develop innovative data systems for mineral exploration, collaborating closely with geologists and data scientists to improve exploration success rates. You'll own projects end-to-end, engage with users, and create scalable, production-quality solutions for complex geological challenges.

Build and maintain product features that streamline property transactions. Use LLMs and AI coding agents to accelerate development, debug issues, and iterate rapidly. Own tasks from day one, collaborate with a small team, and apply practical problem-solving to deliver customer-facing improvements.

Design, build, and maintain large-scale distributed data systems and pipelines for blockchain analytics. Ship production code, drive technical direction, mentor engineers, improve reliability, observability, and cost efficiency, and collaborate with product, data science, and intelligence teams.

Senior full-stack product engineer owning large product areas end-to-end: research, write specs, design wireframes, implement features across frontend and backend, and collaborate closely with product, design, and infra. Focus on solving customer problems, building durable abstractions, and shipping high-quality, scalable software.

Senior full‑stack product engineer owning a large product area end-to-end: research customers, write specs and wireframes, design and implement features across frontend and backend, collaborate with product and design, and ship high-quality scalable software.

Lead design, develop, test, deploy, and support enterprise Appian workflow and case-management applications. Build integrations (REST/SOAP), enforce engineering best practices, support CI/CD and production deployments, tune performance, collaborate with stakeholders, and incorporate risk controls.

Lead design, development, and maintenance of scalable software systems. Provide technical leadership across multiple teams, act as prime technical contact, collaborate with customers and partners, mentor engineers, and contribute to architecture, delivery planning, and DevOps practices.

Lead design, development, deployment and maintenance of critical software systems. Own team deliverables, collaborate with product, frontend and QA, mentor junior engineers, and work across the full SDLC with CI/CD, containerisation and cloud platforms to deliver scalable, high‑quality solutions in an agile environment.

Lead the delivery of scalable software solutions to improve patient outcomes in primary care. Collaborate across teams to define requirements and drive impactful changes.

Design, build, and operate the Axon Alerts platform: ingest events from 1P/3P sources, enrich metadata, apply routing rules, and deliver notifications across channels. Ensure high availability and low latency, lead architecture reviews, improve observability and operational excellence, collaborate with Product and Design, and mentor other engineers.

Lead design and build of a greenfield, ultra-low-latency C++ trading platform covering execution, market data, order and risk management. Implement direct exchange connectivity, optimize microsecond/nanosecond performance, collaborate with traders and quants, own systems end-to-end from design through production support for live trading.

The Senior Software Engineer will architect and build backend systems, own clinical system integrations, improve performance, and shape engineering culture.

Develop and maintain FortiDLP server-side services, building APIs, databases, and integrations. Own features from design through delivery, write and review code and tests, ensure code quality and secure practices, collaborate cross-functionally, and support high-volume data pipelines and operational tasks as needed.

Design, implement, and maintain scalable Java-based software solutions. Collaborate across the SDLC with stakeholders and development teams, integrate DevOps and CI/CD practices, support operational tasks, ensure security and performance, drive feature development, conduct code reviews, and stay current with emerging technologies.

Design, ship, and maintain telecommunication capture services in a multi-cloud environment. Modernise and operate resilient audio/video capture platforms, support production systems, and collaborate with product and customer teams to deliver robust VoIP solutions.

Product-minded full‑stack senior engineer (backend-leaning) to build and scale NHS-facing systems. Ship high-quality TypeScript/React code, design and consume APIs, handle distributed-systems risks, and influence product direction. Work autonomously in small squads, solve performance and usability issues, and deliver reliable experiences for clinicians and patients.

Lead the development and maintenance of high-performance cross-platform desktop and mobile applications for HiFi audio. Drive technical direction, mentor team members, and innovate audio streaming solutions while ensuring product scalability and performance.

The Principal Software Engineer will lead client engagements, mentor teams, and ensure technical decisions align with business objectives, focusing on software craftsmanship and modernization.