Senior Frontend Engineer: Build Fast, Scalable Web & Mobile

Trading-21; Greater London; On-site; GBP 85,000 - 125,000; Full time

Job summary

Trading-21 is seeking Senior Frontend Engineers to build and scale frontend features across web and mobile. You’ll work in small autonomous squads with a weekly release cycle and end-to-end ownership from problem definition through production.

You will design and evolve React and React Native systems, address performance bottlenecks and collaborate with product, backend engineering and QA to deliver high-quality user experiences.

Qualifications

• Proven ownership of production frontend systems built with React or React Native and TypeScript.
• Strong knowledge of React rendering, component boundaries, data flow and state management.
• A track record of designing maintainable frontend architecture and reusable abstractions.
• Practical experience diagnosing performance problems in complex web or mobile products.
• Sound testing judgement across unit, end-to-end and visual-regression coverage.
• Clear, structured problem-solving and the ability to explain technical decisions and trade-offs.
• Strong engineering fundamentals, product judgement and confidence learning unfamiliar technologies.

Responsibilities

• Own complex frontend features end to end across web and mobile.
• Design and evolve React and React Native systems, shared libraries and durable abstractions.
• Identify and resolve rendering, state-management, bundle and runtime-performance bottlenecks.
• Use TypeScript to make behaviour explicit and prevent defects rather than suppressing type errors.
• Work closely with product, backend engineering and QA to turn complex requirements into simple user experiences.
• Keep quality high through code review, unit, end-to-end and visual-regression testing.
• Share knowledge, mentor colleagues and raise the frontend engineering standard.

Skills

React/TypeScript

React Native

Frontend ownership

Performance optimization

Testing discipline

Problem solving

Job description

Trading-21 is seeking Senior Frontend Engineers to build and scale frontend features across web and mobile. You’ll work in small autonomous squads with a weekly release cycle and end-to-end ownership from problem definition through production.

You will design and evolve React and React Native systems, address performance bottlenecks and collaborate with product, backend engineering and QA to deliver high-quality user experiences.