aSenior Front-End Developer

{ "@context": "http://schema.org", "@type": "JobPosting", "baseSalary" : { "@type": "MonetaryAmount", "currency": "EUR", "value": { "@type": "QuantitativeValue", "minValue": 30000, "maxValue": 50000.00, "value": 50000.00, "unitText": "YEAR" } }, "datePosted": "2026-04-12", "validThrough" : "2026-06-28", "description": "Brain Rocket is a global company creating end-to-end tech products for clients across Fintech, i Gaming, and Marketing. Young, ambitious, and unstoppable, we've already taken Cyprus, Malta, Portugal, Poland, and Serbia by storm. Our BRO team consists of 1,300 bright minds creating innovative ideas and products. We don't follow formats. We shape them. We build what works, launch it fast, and make sure it hits. We're looking for aSenior Front-End Developer (React)to join our team in our office in Valencia. 5+ years of professional front-end development. 3+ years using React (16.8+) in production environments. Strong proficiency in Type Script, including strict-mode. Hands-on experience writing unit tests (Jest) and E2 E tests (Cypress or Playwright), with CI integration. Experience with Tan Stack Query (or similar) for REST/Graph QL data-fetching. Experience with React Hook Form (or equivalent) and schema-based validation for complex forms. Knowledge of modern state management patterns using Zustand, Redux, or equivalent. Familiarity with modern build tooling like Vite (preferred), Webpack 5, or similar ES-modules pipeline. Intermediate level of English. Would be a plus: Proven ability to refactor large front-end codebases-optimising data-fetch patterns, state management, and component architecture. Deep familiarity with modern data-grid libraries-preferably Tan Stack React Table 8 (virtualised rows, column meta, server-side filtering/pagination). Experience building UIs with Chakra UI or equivalent component libraries with custom theming. Familiarity with Storybook. Experience designing and implementing infrastructure for AI agent systems. Maintain and enhance existing React/Type Script UIs, emphasizing stability. Build new features on top of an established system, following defined architecture and design patterns. Drive stability efforts - quickly resolve critical bugs and regressions, and proactively refactor fragile parts of the codebase. Collaborate closely with Product, Design, and Backend teams to deliver frontend features on schedule without sacrificing code quality. Participate actively in code reviews, mentor teammates, and help maintain high standards for code hygiene, CI quality, and technical documentation. We offer excellent benefits, including but not limited to: Learning and development opportunities and interesting, challenging tasks. Official employment following the laws of Spain/EU, registration of family members. ️ Relocation package (tickets, staying in a hotel for 2 weeks). ️ Company fitness corner in the office for employees. Opportunity to develop language skills and partial compensation for