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Full-stack engineer who delivers production-ready SaaS from concept to deployment. I build custom front-ends in Next.js, TypeScript and Tailwind CSS on Node.js/Express REST backends, integrating Stripe subscription billing, role-separated authentication, and production-grade admin tooling. I also ship AI features using OpenAI APIs, LangChain and RAG pipelines (with vector DBs and MCP), and I have led end-to-end delivery of hospitality SaaS products—from empty repo to multiple live properties—owning the PostgreSQL data model, migrations, and deployment. Available remotely for part-time contract work invoicing from Andorra.…Full-stack engineer who delivers production-ready SaaS from concept to deployment. I build custom front-ends in Next.js, TypeScript and Tailwind CSS on Node.js/Express REST backends, integrating Stripe subscription billing, role-separated authentication, and production-grade admin tooling. I also ship AI features using OpenAI APIs, LangChain and RAG pipelines (with vector DBs and MCP), and I have led end-to-end delivery of hospitality SaaS products—from empty repo to multiple live properties—owning the PostgreSQL data model, migrations, and deployment. Available remotely for part-time contract work invoicing from Andorra.

Netra-Luis Castells Niyomsilp

Full Stack Developer, AI Engineer, Back-End Developer, +2

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Full-stack engineer who delivers production-ready SaaS from concept to deployment. I build custom front-ends in Next.js, TypeScript and Tailwind CSS on Node.js/Express REST backends, integrating Stripe subscription billing, role-separated authentication, and production-grade admin tooling. I also ship AI features using OpenAI APIs, LangChain and RAG pipelines (with vector DBs and MCP), and I have led end-to-end delivery of hospitality SaaS products—from empty repo to multiple live properties—owning the PostgreSQL data model, migrations, and deployment. Available remotely for part-time contract work invoicing from Andorra.…Full-stack engineer who delivers production-ready SaaS from concept to deployment. I build custom front-ends in Next.js, TypeScript and Tailwind CSS on Node.js/Express REST backends, integrating Stripe subscription billing, role-separated authentication, and production-grade admin tooling. I also ship AI features using OpenAI APIs, LangChain and RAG pipelines (with vector DBs and MCP), and I have led end-to-end delivery of hospitality SaaS products—from empty repo to multiple live properties—owning the PostgreSQL data model, migrations, and deployment. Available remotely for part-time contract work invoicing from Andorra.

Available to hire

Full-stack engineer who delivers production-ready SaaS from concept to deployment. I build custom front-ends in Next.js, TypeScript and Tailwind CSS on Node.js/Express REST backends, integrating Stripe subscription billing, role-separated authentication, and production-grade admin tooling.

I also ship AI features using OpenAI APIs, LangChain and RAG pipelines (with vector DBs and MCP), and I have led end-to-end delivery of hospitality SaaS products—from empty repo to multiple live properties—owning the PostgreSQL data model, migrations, and deployment. Available remotely for part-time contract work invoicing from Andorra.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Beginner

Language

Spanish; Castilian

Fluent

Catalan; Valencian

Fluent

English

Advanced

German

Beginner

Work Experience

Technical Lead (Freelance) at Montpackers (Guest Experience)

January 1, 2026 - Present

Delivered a hospitality SaaS from concept to deployment using a Next.js/TypeScript front-end, Node.js services, and a PostgreSQL (Supabase) data model with all migrations. Built a self-managed multilingual CMS for non-technical hotel staff, including automatic guest-language detection, transactional email via the Loops API, and an omnichannel sync layer to keep kiosk, web and app consistent from a single source of truth. Rolled out to 30+ hotels and campings (up to 62% fewer front-desk questions in the first month), with many properties going live the same day the kiosk is installed.

AI Engineer (Freelance) at Government of Andorra

September 1, 2024 - January 31, 2025

Built Meritxell, a public AI assistant answering citizen questions about the EU Association Agreement. Anchored every response in official documentation via RAG so answers remain accurate and traceable.

Co-Founder & Lead AI Engineer at The Agents Lab Andorra la Vella

September 1, 2024 - Present

Integrated AI features into client products using OpenAI APIs, LangChain, RAG pipelines, vector databases and MCP, deployed on serverless infrastructure. Built chatbotfor.ai, a no-code, multi-tenant platform enabling clients to create and deploy their own AI assistants, covering the full stack from data model and product architecture to deployment.

Full-Stack Developer (Freelance) at Legal Pigeon

December 1, 2023 - October 31, 2024

Delivered full-stack work in Node.js and React for a legal-tech SaaS platform, shipping features end to end from the data layer to the user interface with a strong UI focus. Earlier work included Stripe billing integration for recurring subscriptions, webhooks and the customer portal, with test coverage using Jest and Cypress.

Full-Stack Tech Lead at worX Software Ltd

April 1, 2023 - December 31, 2023

Tech led full-stack product development with Node.js and React on AWS, owning architecture decisions and delivery across the stack.

Backend / Full-Stack Developer at CORUS Consulting

June 1, 2019 - March 31, 2023

Built backend and full-stack solutions using Node.js, TypeScript and SQL in cross-functional teams. Containerized services with Docker and Kubernetes; earlier work included Java and WebMethods engineering.