Front End Developer - Manager

Role purpose You'll build the user interfaces for a multi-year programme modernizing a large portfolio of middle-office applications and moving them to AWS. This is a hands-on senior development role. You'll build data-heavy, real-time ReactJS/TypeScript applications that replace legacy desktop and web UIs. You'll own front-end integration with back-end services over REST APIs, WebSockets and Server-Sent Events (SSE). You'll also set front-end standards and tooling for the team, and use AI coding tools as part of your everyday work. Key responsibilities Front-end development Design and build complex ReactJS/TypeScript applications for trade processing, reconciliation, settlement and operations monitoring users. Build high-performance, data-heavy UIs: large grids (e.g. AG Grid), virtualised lists, filtering, dashboards and live status views. Design reusable component libraries, state management (e.g. Redux Toolkit, Zustand, React Query) and accessible, consistent UI patterns. Write clean, modern JavaScript (ES6+) and strongly typed TypeScript, and keep API contracts type-safe. You will have decent experience of understanding and changing Java backend code Real-time and API integration Integrate with server-side services over REST APIs, including authentication, pagination, caching, retries and error handling. Build robust WebSocket clients (native WebSocket, STOMP or Socket.IO) for two-way, low-latency updates. Handle reconnects, heartbeats, back-pressure, message ordering and subscription management. Implement SSE streams for one-way server push (e.g. job status, cycle progress, alerts), including reconnection and event replay. Choose the right pattern (REST, WebSocket or SSE) for each use case, working with back-end engineers on message design and contracts. Make real-time screens perform well under heavy update volumes: batched rendering, memoisation and throttling. Build tooling and quality Set up and maintain front-end builds with npm/pnpm and Vite, including workspaces/monorepos, dependency management, environment configuration and bundle optimisation. Work with DevOps on CI/CD pipelines (Harness/GitHub Actions) for front-end build, test and deployment. Write unit, component and end-to-end tests (Vitest/Jest, React Testing Library, Playwright or Cypress), and use mock servers for REST, WebSocket and SSE testing. Handle front-end security: SSO/MFA integration, token handling, XSS/CSRF protection and dependency vulnerability scanning. AI-assisted development Use GitHub Copilot, Claude Code and/or Devin to speed up component building, refactoring, test generation and legacy UI analysis. Review all AI-generated code for correctness, accessibility, performance and security before merging. Leadership Set front-end standards, review code and mentor other developers. Work with business analysts and users to turn legacy screens and workflows into modern, usable interfaces. Support releases, cutovers and early-life support.