We are looking for a Senior AI Full Stack Developer to join a global team responsible for the end-to-end ownership of a worldwide B2B platform.

In this role, you will design, build, and maintain high-performance, scalable, and secure web applications that support business-critical digital commerce solutions. You will collaborate with international engineering teams, contributing to a modern cloud-native architecture while ensuring excellent user experience, reliability, compliance, and operational efficiency.

? What you'll do

? Design, develop, and maintain enterprise-grade Full Stack applications supporting a general B2B platform

? Build modern frontend applications using React and Next.js

? Develop scalable backend services and REST APIs using Node.js and/or Java Spring Boot

? Build and deploy cloud-native applications using AWS

? Collaborate with multiple engineering teams working on shared codebases

? Deliver high-quality software following clean architecture and software engineering best practices

? Optimize application performance, scalability, security, and reliability

? Implement unit, integration, UI, and automated testing strategies

? Contribute to CI/CD pipelines and modern DevOps practices

? Participate in Agile/Scrum ceremonies and cross-functional product teams

? Collaborate with architects, product managers, UX designers, QA engineers, and international stakeholders

? Contribute to technical decisions, code reviews, mentoring, and engineering best practices

? Must Have

? 5+ years of experience as a Full Stack Software Engineer

? Strong experience with React and/or Next.js

? Experience developing backend applications using Node.js and/or Java Spring Boot

? Strong knowledge of JavaScript, TypeScript, or Java

? Experience designing and integrating REST APIs

? Hands-on experience building applications on AWS

? Experience working with shared repositories using GitHub





? Experience with CI/CD pipelines

? Experience implementing unit, integration, UI, and automated testing

? Experience working in Agile/Scrum environments

? Strong software engineering fundamentals, problem-solving skills, and collaborative mindset

? Fluent English (mandatory)

? Experience integrating LLMs, Generative AI, RAG, or Agentic AI into web applications

? Experience with data pipelines and AI-enabled backend services

? Familiarity with AI development tools such as Cursor or Claude

? What we offer

? Hybrid model — 3 days onsite in Barcelona

? International environment with global engineering teams

? Opportunity to work on a global B2B platform used worldwide

? Why join Capitole?

? People-first culture with an inclusive and collaborative environment

? Work on enterprise-scale digital commerce solutions with modern technologies

☁️ Build cloud-native applications on AWS

? Opportunity to contribute to AI-enabled software initiatives

? €1,200 annual training budget

? Private health insurance

? Flexible compensation plan

⚡ Flexible working hours

?️ Wellhub: fitness, wellness, and mental health support

⚽ Company-sponsored football and paddle teams

? Team buildings, technical communities, and international events

✨ Want to know more about us? Click here and discover all the details.

? Curious about our culture? Check out what people are saying about us on Glassdoor.

? We know that not every candidate will meet 100% of the requirements. If your experience is close and you're excited about the opportunity, we'd love to hear from you!

? Ready for the challenge? Apply now!

Empowering People, Unlocking Innovation.

Information Security Notice

- The employee will have access to confidential information related to Capitole and the assigned project.
- Compliance with internal security and information protection policies is mandatory.
- NDA signature required.

📌 Senior AI Full Stack Developer - barcelona
🏢 Capitole
📍 Barcelona