Senior Full Stack Developer

💼 Senior Full Stack Developer (React + PHP) 📍 Madrid (hybrid)

🕒 Full-time 👋 About FERO FERO is reinventing checkout for eCommerce. We build high-performance, adaptive checkout experiences that help merchants increase conversion and revenue. Backed by top-tier VCs, we’re building from Madrid with a strong focus on performance, data, and real impact. 🚀 Why join FERO? Work on a core product that directly impacts revenue

High ownership and real technical challenges

Modern stack + real scale problems

Direct collaboration with product and leadership

Competitive salary + equity

Fast-growing, ambitious team 🎯 About the role We’re looking for a Senior Full Stack Developer to build and scale our next-generation checkout experience. You’ll work across the full stack — building high-performance React interfaces and contributing to PHP backend systems powering real eCommerce transactions. 👉 This is a product-focused role — everything you build impacts conversion. 💥 What you’ll do Build end-to-end features across frontend and backend

Develop modern, responsive interfaces using React, JavaScript, HTML, and CSS

Integrate with backend systems (PHP) and APIs (REST, GraphQL)

Work with payment systems, checkout flows, and eCommerce integrations

Collaborate closely with engineers, product, and design

Write clean, maintainable, and scalable code

Optimize performance, accessibility, and UX

Use data and experimentation to improve conversion 🧠 Core requirements 5+ years of experience as a Full Stack Developer

Strong experience with React and modern JavaScript

Solid PHP knowledge (APIs, backend logic, integrations)

Experience working with REST and/or GraphQL APIs

Experience building or working with eCommerce systems ➕ Nice to have Experience with WooCommerce or Magento

Experience with payments or checkout systems

Strong understanding of performance optimization

Familiarity with experimentation / A/B testing 🧬 Who you are Product-minded — you care about impact, not just code

Strong ownership — you take things from idea to production

Detail-oriented and quality-focused

Curious and always learning

Team player who enjoys building with others 🧭 What makes this role different You’re not just building features —

you’re working on the most critical part of eCommerce: checkout. Every improvement you ship directly impacts revenue. 💼 What we offer Competitive salary + equity

Private health insurance (partially covered)

Hybrid work (3 days office / 2 remote)

Real growth opportunities as we scale

Collaborative and high-performance environment 🧭 Hiring process Application review

Intro call (15–20 min)

Technical interview (deep dive into experience + problem solving)

Final interview with founders

Offer 🚀 ⚡ Ready to build what matters? If you want to work on real product challenges, ship fast, and see the impact of your work — we’d love to meet you. 👉 Apply now and help us redefine checkout.