React Developer

• The React developer will be working on the build of a product-grade React & Typescript application from greenfield through to a maintainable, globally scalable, and secure product
• Greenfield build to production: build a production-grade React & TypeScript application from zero to a maintainable, scalable platform
• Data-dense UI delivery: Deliver high-quality UI for dashboards, tables/grids, filtering/sorting, drilldowns, forms, and multi-step workflows
• State & data patterns: implement robust client-state and server-state patterns including loading/error states, retries, resilience, caching and invalidation
• Performance engineering: Drive render efficiency, bundle size control, code splitting, virtualisation for large datasets, network efficiency, and instrumentation/observability
• API contract collaboration: Work with Back End engineers on predictable API contracts via BFF (pagination, aggregation shapes, response models, error semantics)
• Security-by-design delivery: Apply secure Front End practices (auth/session hygiene, safe client-side data handling, dependency hygiene)
• Accessibility & usability: Ensure keyboard support, focus management, ARIA where appropriate, and strong empty/error states for complex UIs
• Quality discipline: Maintain a strong quality bar through code review, automated tests, CI quality gates, and release readiness
• Delivery pipelines: Contribute practically to build tooling, CI checks, deployment considerations and environment configuration
• Documentation: Produce concise, proper documentation for key decisions, patterns and non obvious implementation details

• The React Developer will have significant commercial experience within financial services, building modern React applications (hooks, composition patterns, controlled/uncontrolled components, state lifting, modularisation
• Demonstrated ability to operate as a senior engineer: strong judgement, proactive risk management, pragmatic delivery, and high code quality standards
• Proven ability to design Front End architecture for long-term maintainability (module structure, feature boundaries, shared UI patterns, conventions)
• Comfortable establishing foundations early (linting/formatting, project structure, testing strategy, patterns for API access, error handling, and observability hook)
• Experience shipping complex interface: tables/grids, dashboards, rich filters, multi-step workflows, and interaction-heavy UIs
• Familiarity with performance constraints caused by large datasets and frequent UI interactions (virtualisation, event handling)
• Strong TypeScript capability across: typed component APIs (props/contracts), shared domain models/DTOs, safe typing around API responses, error and async flows, sensible user use of generics/utility types without over-engineering
• Proven judgement selecting and implementing state patterns: clear separation of UI state vs server state, caching & invalidating strategies, avoiding unnecessary re-render and state leaks
• Experience with modern tooling such as TanStack Query
• Strong awareness of security/performance best practices in client data fetching and caching (handling auth/session, sensitive data considerations, preventing accidental data leakage, safe error handling)
• Experience writing and maintaining meaningful automated tests with a strong judgement on what to test, keeping suites fast and avoiding brittleness
• Evidence of improving real-world performance (bundle analysis, render optimisation, code splitting, virtualisation)
• Ability to keep UI responsive under heavy interaction patterns and large datasets.
• Security-conscious delivery
• Security-minded development practices (OWASP awareness, auth/session hygiene, dependency hygiene)
• Comfortable operating in environments where confidentiality, disciplined change control and auditability matter
• Data visualisation (interactive charts; performance-conscious rendering)

The salary range/rates of pay is dependent upon your experience, qualifications or training.

Robert Half Technology are assisting a market leading financial services organisation to recruit a React Developer on a contract basis. Hybrid working - London based, * Market leading financial services organisation with offices in London * Hybrid working - London based