Senior Frontend Developer

Senior Front End Engineer (React / TypeScript) London Hybrid (2-3 days per week) Build the platform that powers client onboarding at scale We're looking for a Senior Front End Engineer to help shape and build a modern onboarding and account management platform used by businesses across multiple customer types, including corporates, funds, intermediaries and complex account structures. You'll join a highly autonomous engineering team responsible for creating exceptional user experiences within a sophisticated, form-driven application. This is a role for someone who enjoys solving complex frontend challenges, influencing architecture, and taking ownership from design through to production. We're looking for engineers who care deeply about customer outcomes, software quality, and building the right solutions, not just shipping features. The Opportunity You'll be working on a modern React-based single-page application, building complex onboarding journeys, integrating with external services, and helping define the future direction of the platform's frontend architecture. You'll have the freedom to make technical decisions, contribute to architectural discussions, and work in an environment where engineers are trusted to own what they build. What You'll Be Doing Design and develop new features within a modern React single-page application.Build and maintain complex user journeys involving multi-step workflows and advanced form validation.Take ownership of functionality from concept through to production.Define and influence frontend architecture, documenting and presenting technical decisions.Ensure security, reliability and observability are considered from the outset.Build highly accessible, responsive and user-friendly interfaces.Integrate with third-party platforms including identity verification, document management and API services.Use AI-assisted development tools effectively and responsibly.Review code, mentor team members and contribute to engineering best practices.Collaborate closely with product, design and engineering teams to deliver outstanding user experiences. What We're Looking For Essential Experience Strong commercial experience building and maintaining production-scale applications with React and TypeScript.Deep understanding of modern frontend architecture and state management.Experience building complex, form-driven applications with sophisticated validation and business rules.Strong knowledge of multi-step workflows, state persistence and long-running user journeys.Expertise in server-state management, including caching, invalidation and data-fetching strategies.Experience integrating third-party services and APIs.Strong understanding of authentication, authorisation, roles and permissions.Solid testing practices with experience using modern frontend testing frameworks.Strong accessibility knowledge with experience building applications to WCAG 2.1 AA standards.Experience working with component-based design systems and reusable UI libraries.Practical experience using AI development tools within software delivery teams.Excellent communication skills and the confidence to challenge ideas while remaining collaborative and outcome-focused. Technical Skills React 18TypeScript (Strict Mode)TanStack Query, Form and RouterTailwind CSSRadix UI / shadcnVitestReact Testing LibraryMock Service Worker (MSW) Nice to Have While not essential, experience in any of the following would be highly beneficial: Auth0 or similar identity providersSentry or comparable monitoring and error-tracking platformsAzure Static Web AppsAzure DevOpsCI/CD pipelinesVite performance optimisation and bundle analysisStorybook or other component documentation platformsWebSockets or SignalRClient onboarding platformsKYC/KYB workflowsRegulated financial services environments If you don't have industry-specific experience but are an exceptional engineer, we'd still love to hear from you. Technology Environment React 18TypeScript (Strict Mode)ViteAzure Static Web AppsAzure DevOpsGrafanaApplication InsightsAI-assisted development toolsStorybookMacBook Pro workstation Why Join? End-to-end ownership of the software you build.Influence technical direction and architectural decisions.Work on genuinely complex frontend engineering challenges.Modern technology stack and engineering practices.Highly autonomous teams with rapid decision-making.Strong culture of quality, collaboration and continuous improvement.Opportunity to work alongside talented engineers solving real-world problems at scale. If you're passionate about building high-quality React applications, enjoy solving complex user experience challenges, and want the freedom to shape both product and architecture, we'd love to hear from you.