Top Software Engineer Jobs in London

The Junior Ubuntu Software Engineer will design, build, and ship software, focusing on quality and resilience, while engaging with the open source community.

Lead Mark43's AI-enabled engineering initiative by designing and orchestrating multi-agent systems that plan, write, review, test, and deploy software. Write prompts, scaffolding, and tool integrations (VCS, test runners, internal APIs), evaluate agent performance, prototype LLM-based workflows, collaborate cross-functionally, mentor teammates, and contribute to on-call rotations.

Hybrid Software Developer in Test (SDET) to build a new digital bank. Develop object-oriented code with Kotlin/Java/JavaScript, design for testability, implement automated tests (Cucumber/Capybara/Selenium), integrate CI (Jenkins/TeamCity), review designs, analyze code, assess risk, and use Jira for tracking.

Design, write and maintain automated Selenium web test suites, create test plans, improve CI pipelines, oversee deployments and releases, and mentor junior SDET engineers.

As a Full-Stack Engineer at Electric Twin, you will build and evolve complex systems and user interfaces, emphasizing thoughtful engineering across the full stack, from front to backend.

Develop and optimize large-scale compute systems for AI workloads, improving infrastructure reliability and performance across various layers of the stack.

Designs, develops, and operationalizes large-scale backend, API, graph, AI, and machine learning solutions. Responsibilities include technical leadership, cloud-native architecture, roadmap development, testing, code reviews, mentoring, recruitment, stakeholder communication, and improving engineering processes. The role requires extensive Java and Spring experience, AWS cloud development, RESTful APIs, stream processing, low-latency applications, generative and agentic AI, and strong software delivery practices.

Build and productionize tooling that compiles complex Python packages such as NumPy, SciPy, and PyTorch from source. Develop conda recipes, build tools, automation, and release processes; partner with packaging and distribution teams; mentor engineers; and lead postmortems, capacity planning, and incident response. The role also shapes technical strategy, architecture, project scope, and delivery decisions for build and distribution infrastructure.

Design and build internal systems and tools across the firm, including infrastructure, monitoring, and tooling used by trading, research, and support teams. Collaborate with engineers, contribute to open source projects, and solve practical problems using strong programming and problem-solving skills.

Build and maintain the control planes, automation, and observability for a global fleet of machines. Develop production-quality Go services for provisioning, health checks, upgrades, and incident remediation. Architect high-throughput, low-latency networking, improve utilization and power-to-performance, and collaborate with product and platform teams on storage-aware scheduling and developer-facing features.

Build and optimize backend microservices, APIs, and data models for a global payments platform. Collaborate with client teams, lead architecture for high-concurrency low-latency systems, and ensure testing, monitoring, deployment, and secure data handling for scalable financial products.

Design, build, and maintain backend API and database services for a cloud PBX platform. Drive architecture, performance optimization, debugging, CI/CD and test automation, and collaborate with QA. Mentor peers and raise engineering standards while safely evolving high-load, networked systems.

Develop and maintain the backend ecosystem for the Alta Video Management System, focusing on cloud-based distributed systems and coding quality.

Build and operate backend and platform services for ACRA, a secure Kubernetes platform. Develop Go services, design scalable distributed systems, implement CI/CD/GitOps workflows, manage containers and secrets, improve observability and incident response, and own platform features for isolation, policy enforcement, and auditability.

Build and maintain APIs and systems for money movement, debug production issues, mentor engineers, and collaborate with stakeholders.

Design and maintain scalable systems, collaborate with cross-functional teams, and enhance internal tooling while focusing on reliability and performance in infrastructure.

As a Software Engineer, you will develop solutions for a cutting-edge trading system, enhance a petabyte-scale data platform, and apply engineering best practices.

Lead the Research team in developing scalable machine learning solutions, mentoring junior engineers, optimizing model training, and collaborating on real-world engineering problems.

Responsible for developing and optimizing trading systems, collaborating with quants and traders, and driving innovative trading application projects.

Own feature lifecycle in a cross-functional squad, design scalable systems, set technical standards, lead SRE/observability, mentor engineers, coordinate cross-team initiatives, and drive AI-augmented development workflows.

Build and operate scalable, low-latency APIs, event-driven services, integrations, and web applications supporting membership and loyalty experiences. Integrate and extend Antavo with commerce, CRM, CDP, marketing, and data platforms. Apply distributed-systems, reliability, observability, and security practices; troubleshoot production issues; contribute to reusable engineering assets; and mentor junior engineers.

Leads quality engineering for consumer-facing web and mobile experiences. Designs scalable automation frameworks, develops functional, API, integration, regression, and end-to-end test suites, and integrates quality gates into CI/CD pipelines. Validates accessibility, performance, reliability, and cross-device behavior; investigates defects, analyzes quality metrics, and drives continuous improvement. Collaborates with product and engineering teams, mentors engineers, and applies AI-assisted testing practices.

Design, build, optimize, and support scalable consumer-facing mobile applications across iOS and Android using React Native, TypeScript, and JavaScript. Develop native integrations, reusable components, secure architectures, API integrations, automated testing, CI/CD pipelines, and production monitoring. Collaborate cross-functionally, contribute to releases and Agile delivery, mentor engineers, conduct code reviews, and drive mobile engineering excellence, accessibility, performance, and reliability.

Lead the architecture, development, and deployment of production-grade AI, machine learning, software, and infrastructure systems. Establish scalable ML deployment standards, collaborate with engineering, data science, product, and commercial teams, advise clients, and mentor junior engineers. The role requires strong technical leadership, cloud expertise, client-facing communication, and the ability to deliver robust systems in a fast-paced environment.

Design, develop, and maintain matching engines, FIX gateways, and low-latency trading applications using Java and C++. Implement efficient in-memory data structures, optimize networking and concurrency, troubleshoot production issues, and collaborate with trading, product, and infrastructure teams across the full software development lifecycle.