companyYopeso logo

Senior Full Stack Developer (Node.js Focus) – Open-Source AI Platform

YopesoMadrid, Comunidad de Madrid, Spain
Hybrid Contract

Clicking Apply Now takes you to AutoApply where you can tailor your resume and apply.


Unlock Your Potential

Generate Job-Optimized Resume

One Click And Our AI Optimizes Your Resume to Match The Job Description.

Is Your Resume Optimized For This Role?

Find Out If You're Highlighting The Right Skills And Fix What's Missing

Experience Level

Senior

Qualifications

RequirementsAbout the ProjectWe are developing an advanced, open-source AI conversational platform that integrates various AI providers to provide a rich, state-of-the-art user experience. We seek a seasoned Senior Full Stack Developer to become an integral part of our core team as a B2B partner. This role is primarily full-stack, with approximately 80% of your responsibilities centered on enhancing the Backend architecture (Node.js), while occasionally contributing to the modern React frontend. If you have a passion for LLMs, prompt engineering, and building robust, scalable systems, this project is tailor-made for you. Setup & Work ArrangementContract: 100% B2B / Independent Contractor (must be registered as an Autónomo or have a corporate entity in Spain). Location: Hybrid. We require your presence at our Madrid office 2-3 days per week for architectural alignment, team syncs, and workshops. The remainder of the time can be remote. Language: Fluent English is a must. What You Will DoTake charge of backend components to construct a sophisticated AI chat platform. Integrate new AI providers (such as OpenAI, Claude, etc.) and develop complex chat functionalities. Design and optimize database structures using MongoDB and PostgreSQL. Implement and maintain real-time features utilizing WebSocket connections. Ensure code quality through automated testing and engage in meticulous code reviews. Deploy and maintain containerized applications.

About the job

About Yopeso

Yopeso has delivered software solutions for nearly 20 years, building both large-scale applications and specialized products. Our team includes over 300 professionals working from five locations worldwide. We focus on growth, transparency, and professionalism in every project.

We value authenticity, curiosity, and ambition. These principles guide our work and shape our relationships with colleagues and partners. Trust, integrity, and transparency are central to how we do business. Our teams strive to develop secure, high-quality software that performs reliably.

Collaboration is at the heart of our approach. Agile teams work together efficiently, driven by curiosity and ambition, to deliver products that make a difference and reflect our core values.

About Yopeso

Yopeso is a leading software development company with 20 years of experience, specializing in diverse software products, including large-scale applications and tailored solutions. We prioritize a culture of growth, transparency, and professionalism, with a dedicated team across multiple locations.

Similar jobs

Tailoring 0 resumes

We'll move completed jobs to Ready to Apply automatically.