Full Stack Engineer

Are you a developer passionate about crafting exceptional e-commerce checkout experiences?

At FERO, we’re looking for a Full Stack Engineer to lead the development of our next-generation checkout experience. You’ll build performant, user-friendly interfaces in React, and work across PHP backends to deliver seamless and high-performing checkout flows.

Who We Are

We’re FERO, a high-growth startup reinventing the checkout and payment experience to help our customers increase conversion and revenue.

Backed by top-tier VCs, we’re building our future from the heart of Madrid, combining cutting-edge tech with a collaborative, data-driven culture.

We offer competitive pay, employee equity, and the chance to make a real difference in an environment that values curiosity, creativity, and impact.

What You’ll Do

• Develop End-to-End Features: Architect and implement modern, responsive checkout experiences using React, JavaScript, HTML, and CSS — and ensure smooth backend integration with PHP.
• Collaborate Across Teams: Work closely with other software engineers, designers, and product managers to deliver seamless, high-performing user experiences.
• Integrate Systems: Connect to backend APIs (REST, GraphQL), payment gateways, and shipping modules.
• Contribute to Backend Code: Write and maintain PHP code when needed to support frontend logic or improve integrations.
• Maintain Quality: Deliver clean, testable, maintainable code following best practices in performance, accessibility, and security.
• Optimize for Conversion: Use UX best practices and data insights to improve checkout performance and conversion rates.
• Stay Ahead: Keep up-to-date with the latest trends in React, frontend tooling, and e-commerce technology.

Who You Are

• Experienced Full Stack Engineer: 5+ years of professional experience working with both frontend (React, modern JavaScript) and backend (PHP). Experience with WooCommerce or Magento is a plus.
• Strong PHP Knowledge: You can navigate and extend backend systems, build APIs, and contribute to backend architecture.
• E-Commerce Aware: You understand checkout flows, payment integrations, and e-commerce systems.
• API Fluent: Experienced with REST and GraphQL APIs.
• Performance & Accessibility Focused: You know how to build fast and accessible web experiences.
• Collaborative & Curious: You enjoy working in a team and bringing new ideas to the table.
• Eligible to Work in Spain.
• Fluent in English.

What We Offer

• Innovative Environment: Work on cutting-edge solutions in a greenfield setting.
• Growth Opportunities: Join us early and grow with us professionally and personally.
• Collaborative Culture: Be part of a friendly, creative, and supportive team.
• Flexible Work: Hybrid model – 3 days in office, 2 days WFH.
• Competitive Compensation: Great salary, employee equity, and private health insurance partially sponsored by FERO.

Ready to Join Us?

Excited to make a difference? Send us your English CV and let’s build the future of checkout together!