Senior Front End Engineer - AI Products in London

We are Citi's Application, Platform and Engineering team, a start‑up with the exciting mission of shaping the direction of travel for the entire bank under the Chief Technology Office, by defining the tech and engineering strategy for the bank. We are a team of talented engineers, product managers and tech SMEs, taking ambiguous concepts and making them real by engineering cutting edge products at planetary scale! We are solely focused on the most modern technology and engineering disciplines such as generative AI, cloud, security, modern app stacks (with Golang, Gatekeeper), open source and the latest and greatest in the Kubernetes ecosystem.

Generative AI is a growing space, as a result, we ask that you share with us any specific AI engineering projects utilising LLMs that you're proud of in your application. Ideally these projects should show off complex and clever architectures or a systematic evaluation of an LLM's behaviour.

You might be a good fit if you:

• Bring your deep‑dive front‑end engineering expertise from building polished, high‑performance user interfaces for production systems at scale
• Thrive in a results‑driven environment, where flexibility fuels impact
• Be a game‑changer, ready to step beyond your designated role
• Love the synergy of pair programming? So do we!
• A relentless passion to learn more about modern UI/UX paradigms, design systems, and bringing your knowledge to shape Citi's front‑end engineering future.

What you'll do within the Tech Strategy team:

• Build AI‑powered product interfaces from 0‑1 – Engineer production‑grade, business‑facing UI platforms in React with intuitive, accessible, and delightful user experiences from day one
• Design and build sophisticated component libraries and design systems – Create reusable, themeable, and well‑documented React component libraries that ensure visual consistency and accelerate development across the organisation
• Architect scalable front‑end applications – Design robust client‑side architectures using React, TypeScript, and modern state management patterns that handle complex data flows and real‑time interactions at enterprise scale
• Champion front‑end performance and accessibility – Optimise rendering performance, bundle sizes, and Core Web Vitals while ensuring all products meet WCAG accessibility standards
• Drive modern front‑end engineering practices – Establish best practices in component testing, visual regression testing, CI/CD for front‑end assets, and developer tooling to maintain velocity without sacrificing quality
• Mentor and elevate the team – Guide other engineers on React patterns, front‑end architecture, responsive design, and building interfaces that are beautiful, performant, and inclusive

Experience That Will Help You Succeed In This Role:

• Production UI builder – proven track record of architecting and building large‑scale, business‑facing front‑end applications from the ground up, delivering polished products used by thousands of users
• Advanced React expertise – deep proficiency in React (hooks, context, suspense, server components), including performance optimisation techniques such as memoisation, code splitting, lazy loading, and concurrent rendering
• TypeScript mastery – strong command of TypeScript for building type‑safe, maintainable, and self‑documenting front‑end codebases at scale
• Modern state management – extensive experience with state management solutions such as Redux Toolkit, Zustand, Jotai, or React Query/TanStack Query for managing complex client‑side and server‑side state
• Design system and component library development – experience building and maintaining enterprise‑grade design systems using tools like Storybook, Figma‑to‑code workflows, and CSS‑in‑JS solutions (Styled Components, Tailwind CSS, CSS Modules)
• Next.js and modern React frameworks – hands‑on experience with Next.js (App Router, SSR, SSG, ISR) or similar frameworks for building performant, SEO‑friendly, and production‑ready web applications
• API integration and data fetching – expertise in consuming RESTful and GraphQL APIs, implementing optimistic updates, caching strategies, and real‑time data via WebSockets or Server‑Sent Events
• Testing and quality assurance – building comprehensive test suites using Jest, React Testing Library, Playwright, or Cypress, including unit, integration, visual regression, and end‑to‑end testing strategies
• Front‑end performance and observability – deep understanding of browser rendering pipelines, Core Web Vitals optimisation, bundle analysis (Webpack, Vite, esbuild), and front‑end monitoring/error tracking with tools like Sentry or Datadog RUM
• Accessibility and inclusive design – strong knowledge of WCAG 2.1+ guidelines, ARIA patterns, screen reader compatibility, and building interfaces that are usable by everyone, including users with disabilities

What we’ll provide you:

This is a unique role that will put you in the position to be part of a new venture and actively drive change. Every day there will be new challenges that will help you develop new skills that can drive your career.

Benefits:

• 27 days annual leave (plus bank holidays)
• A discretional annual performance‑related bonus
• Private Medical Care & Life Insurance
• Employee Assistance Program
• Pension Plan
• Paid Parental Leave
• Special discounts for employees, family, and friends

Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law.

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