Senior Frontend Engineer

November 5, 2026

Senior

Spain

Description

A senior frontend role building web and mobile trading products used by over 6 million clients with billions in assets. The frontend platform spans web and mobile on TypeScript, React, React Native and React Native Web in an Nx and pnpm monorepo, with about 95% of code reused across platforms. Engineers work in small autonomous groups with a weekly release cycle and own features from problem definition through production.

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

Requirements

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