Senior Frontend Developer – React & Next.js

About the role

SQLI is seeking a Senior Frontend Developer to join its Spain team. You will work in an international, enterprise‑level environment, collaborating with design, product and backend teams to deliver high‑performance, scalable web applications.

Key responsibilities

• Build and maintain scalable frontend applications using React, TypeScript and Next.js.
• Contribute to overall application architecture, code structure and performance optimisation.
• Collaborate closely with UX/UI designers, product owners and backend engineers.
• Ensure high standards of code quality, maintainability and performance.
• Participate in technical discussions, share best practices and mentor junior developers.

Required profile

• 5–10 years of professional frontend development experience.
• Strong sense of ownership and ability to work independently.
• Excellent communication skills in English, especially for explaining technical decisions.
• Experience in ecommerce or complex enterprise environments.
• Proven mentoring and code‑review experience.

Required skills

• React (production level) and TypeScript.
• Advanced JavaScript concepts (async, closures, event loop).
• State management with Redux or similar.
• Next.js, Server‑Side Rendering (SSR) and Client‑Side Rendering (CSR).
• Performance optimisation (lazy loading, Core Web Vitals).
• API integration, familiarity with Node.js/Nest.js backends.
• Design systems and reusable component libraries.

What we offer

• Hybrid work policy with a permanent contract.
• Competitive salary and flexible remuneration (meal vouchers, kindergarten, public transport).
• Private health insurance including dental care.
• Access to Udemy courses, yearly training and certification budget.
• Monday‑Friday schedule with intensive hours on Fridays and all week in July‑August.
• Full salary coverage for sick leave and a clear recruitment process.