Senior Full Stack Developer - Freelancer

Netendersis an international e-commerce group based in Barcelona, operating several leading online stores in Europe and North America. As we continue to grow and innovate, we are developing our own cutting-edge e-commerce Content Management System (CMS) to revolutionize the online shopping experience across our brands.

We are looking for a Senior Full Stack Developer (Freelance) to collaborate with our in-house tech team on high-impact, long-term projects.
👉 This is a freelance / contractor position, with flexible remote work (Barcelona-based candidates are a plus).


Your Role:

As a Senior Full Stack Developer at Netenders, you’ll work on long-term, high-impact projects, including:

• Leading the technical evolution and optimization of our multi-brand e-commerce ecosystem.

• Architecting scalable React frontends and robust Ruby on Rails backend services.

• Developing core CMS features, specifically focusing on complex supplier integrations and high-volume data flows.

• Designing high-performance APIs and back-office tools for pricing and SEO management.

• Ensuring code quality and architectural consistency through expert-level pull request reviews.

• Collaborating with cross-functional teams to translate business requirements into clean, maintainable code.

About you:

You are a self-driven developer with a consultant mindset. You don’t just write code; you design solutions that consider the long-term health of the product. You enjoy the autonomy of freelance work but understand the importance of mentorship and sharing your technical expertise to help internal teams grow.

Requirements:

• 5+ years of experience with Ruby on Rails (v5+), including successful version migrations.

• 3+ years of professional experience building modern interfaces with React.

• Deep understanding of software design patterns and RESTful API architecture.

• Proven track record in e-commerce or handling complex, data-heavy backend systems.

• Strong proficiency with Docker and GIT-based workflows.

• Ability to work autonomously and communicate complex technical concepts clearly.

• Nice-to-have: Experience with Hotwire Native, ElasticSearch, Redis, or Google Cloud Platform.

If you are dynamic, creative, passionate, hardworking, and want to join a company in full expansion, send us your application.

We celebrate diversity and want our team to reflect this inclusively. At Netenders, we are committed to equal employment opportunities regardless of ethnicity, religion, gender, national origin, sexual orientation, age, marital status, disability, gender, gender identity, or gender expression