Global jobs in United States

Opportunity to work in SPAIN (Madrid or Barcelona)

We are looking for a Senior Front End Software Developer to join a cutting-edge team focused on scaling AI assets and building innovative AI-driven products. You will work at the intersection of LLMs, agentic architectures, RAG systems, and modern application development , contributing to the next generation of intelligent interfaces and document-understanding solutions.

In this role, you will collaborate with cross-functional teams, shape new AI-powered applications, and help bring state-of-the-art machine intelligence into real-world products used across the organization.

This position can be fully remote from anywhere in Spain , with monthly workshops in Madrid or Barcelona .

• Build intuitive, responsive, and modern interfaces using React .
• Collaborate with backend, AI, and product teams to deliver end-to-end AI-powered applications.
• Work hands-on with LLMs, RAG architectures, LangChain , and emerging AI technologies.
• Contribute to the design of scalable and maintainable frontend solutions.
• Integrate AI agents, embeddings, vector databases, and retrieval architectures into real applications.
• Participate in Agile ceremonies and work closely with stakeholders to present, explain, and iterate on solutions.
• Support experimentation, prototyping, and optimization of AI models and workflows.

• Strong experience with React.js (Senior level).
• Solid background in full stack development (React + Node.js).
• Hands-on experience with Large Language Models (LLMs) and Retrieval-Augmented Generation (RAG) .
• Knowledge of Python (for AI integrations).
• Experience with Docker and modern cloud environments (AWS and / or Azure).
• Ability to design scalable, reliable, maintainable software architectures.
• Strong communication skills, autonomy, and problem-solving mindset.
• English : mandatory .

• Practical experience with LangChain (highly preferred).
• Familiarity with AI model deployment, inference optimization, and agentic workflows.
• Experience integrating vector databases or embeddings-based search.
• Previous work in Agile or cross-functional product teams.

• People first – diverse and inclusive culture in an international environment.
• Cutting-edge technologies and global projects.
• Career growth and continuous development opportunities.
• Happiness and low turnover rate.
• €1200 per year training budget and learning resources.
• Flexible compensation.
• Private health insurance and benefits package.
• ⚡ Flexible working hours and hybrid model.
• Wellhub : access to fitness, wellness, and mental health support.
• ⚽ Football and paddle tennis teams sponsored by Capitole.
• Team buildings, global events, and strong tech communities.

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

Find out what people are saying about us on Glassdoor Reviews .

If you're passionate about AI, enjoy building seamless user experiences, and want to contribute to products powered by the latest advances in LLMs and agentic architectures — we would love to meet you.

Empowering People, Unlocking Innovation.

• Will have access to confidential information related to Capitole and the project they are working on.
• Must comply with the security policies and internal policies of the company and the client.
• Must sign an NDA.