Descripción de la oferta
Role: Senior Frontend Developer (Contract) Rate: Up to €300 - €400/day Start: ASAP Duration: Open-ended Overview We’re hiring a Senior Frontend Developer to deliver high-performance, conversion-focused web experiences across customer-facing platforms and internal tools. This is a hands-on contract role with immediate impact, suited to someone who thrives in fast-paced, product-led environments. You’ll work closely with Product, Marketing, and Design to build interfaces that are not only technically strong, but also optimised for user engagement and performance. Responsibilities • Build modern, high-converting user interfaces with strong attention to UX and performance • Develop and maintain frontend code for public websites and internal tools • Ensure full responsiveness and cross-browser compatibility • Integrate frontend components into PHP environments using Twig or similar templating systems • Execute A B testing implementations and optimise based on performance data • Conduct thorough browser and device testing to ensure reliability • Collaborate with Product, Marketing, Design, QA, and Operations • Maintain code quality through reviews and best practices • Take ownership of features from development through to production Requirements • 5+ years frontend development experience in production environments • Strong HTML5, CSS3, and JavaScript (ES6+) fundamentals • Solid experience with jQuery and working in PHP-based environments • Experience with Twig or similar templating engines • Strong CSS architecture knowledge, including BEM and SASS • Experience with NPM, Yarn, or similar tooling • Proven ability to build from scratch, not purely framework-driven • Experience with A B testing and performance optimisation • Strong debugging and cross-browser testing skills • Experience working independently with high ownership • Hands-on use of AI tools and ability to implement AI-driven features or agents • Conversational Spanish and intermediate English Nice to have • React and or TypeScript exposure • Experience mentoring or supporting junior developers • Involvement in architecture or technical decision-making