Senior Frontend Engineer

Senior Frontend Engineer

Department: Technology

Employment Type: Permanent - Full Time

Location: London

Reporting To: Matt Millross

Overview of the role

• This role sits in the Accounts tribe, which owns the onboarding of clients and their accounts, including KYC/KYB across corporate, fund, intermediaries and sub-accounts.
• You will be part of a team building a single page application that runs on React 18, Type Script (strict), Tan Stack Query / Form / Router, Tailwind + a Radix/shadcn component system, Vitest + RTL + MSW.
• You make the design calls on your domain and argue them out with the tribe. You build it, you run it, you own it. We are after someone who owns customer outcomes, takes responsibility to ensure their software works and sounds the alarm if we are attempting to build the wrong things.

• Design and build new features in a form-heavy, React single page application
• Thoroughly test everything you build to prove your software works
• Make architectural calls on your domain, record down, present and defend them in front of the tribe.
• Build in security, reliability and observability from the start.
• Use AI tooling well. We use Claude Code daily and we expect judgement about where it earns its place and where it doesn't.
• Review code, raise the standard around you, and help less experienced engineers get better.

• A strong track record of building modern single-page applications in React and Type Script, running in production with real users.
• Complex form engineering. Four onboarding cohorts, branching validation and cross-field dependencies.
• Multi-step flow state. Long journeys that a client leaves and returns to. You must reason about where the state lives and what happens on a reload.
• Server-state architecture. Tan Stack Query at depth: query-key design, cache invalidation, stale policies and prefetch through route loaders.
• Third-party integration. Identity verification, document upload and OpenAPI-generated API clients.
• Roles and permissions. Enforced in the interface as well as the API.
• Testing as a habit. Vitest, React Testing Library and MSW, against a coverage gate that fails the build. You can say what a piece of code is actually protected against.
• Accessibility to WCAG 2.1 AA, in Tailwind with a Radix/shadcn component system and a Storybook library.
• Real experience building software with AI, not just an interest in it. We want someone with a feel for when it helps and when it is quietly making a mess.
• Clear communication with engineers and non-engineers, including the willingness to disagree, and to commit once the call is made.

• Auth0, or a similar identity provider.
• Sentry, or similar error tracking and observability.
• Azure Static Web Apps and Azure Dev Ops, or comparable CI/CD.
• Vite build and bundle work — chunk splitting, bundle analysis, source maps.
• A background in regulated financial services, KYC/KYB or client onboarding.
• Storybook, or another documented component library.
• Real-time updates over Web Sockets or Signal
  
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• If you've done any of it, say so. If you haven't, we'd rather teach you that than compromise on the engineering.

• React 18, Type Script in strict mode and Vite, deployed to Azure Static Web Apps. The business logic sits behind APIs, so the front end owns orchestration, state and complex forms.
• Azure Dev Ops for planning and CI/CD.
• Grafana and Application Insights for observability.
• Claude Code in daily use.
• Autonomous teams, short paths between a decision and it being live
• A macbook pro for your workstation

We believe great people do their best work when they feel supported, rewarded, and empowered to grow. That’s why we offer a benefits package designed to support your career, wellbeing, finances, and life outside of work.

• • 25 days’ annual leave, plus bank holidays
  • An extra day off for your birthday
  • Holiday loyalty scheme rewarding long-term service
  • Work abroad scheme for added flexibility
• • Competitive pension scheme via salary exchange
  • Annual discretionary bonus scheme (eligible after probation)
  • Financial education, planning & coaching platform
  • Interest‑free Season Ticket Loan for London…