Custom software on AWS.
SANFELIU is the studio I founded, and it sells one thing: custom software on AWS. Applications, integrations and automations built to solve one specific problem in your business, at a fixed price, followed by a monthly plan to keep them running. AI comes in where it actually helps. With engineering judgement, not a sales pitch.
- Barcelona · Remote
- 10+ years of engineering
What I do, and how I've done it before.
Custom software on AWS
Applications, integrations and automations built around each company's problem. At Binari, an ETL connecting their clients' ERPs to the warehouse; at Malapell, online business orders with their own admin panel; at Bloome, an MCP server over their backend so clinical staff can query without opening the interface.
- Applications, portals and APIs
- ERP and CRM integrations
- Automation, and AI where it saves hours
The plan that follows handover
Software doesn't end on the day it's handed over. Hosting on AWS, monitoring, backups, security and each month's changes, in a plan shaped around each solution, with no minimum term and the code always in your name.
- AWS hosting and backups
- Monitoring and security
- Monthly changes and improvements
Websites
Websites built by an engineer: fast, maintainable and yours. Robert de Nola's or Habitabio's, AWS migration included. I also migrated and redesigned the Casa dels Peixos site in 2026; that version is no longer online.
- Corporate or product site
- Multilingual and technical SEO
- Hosting and maintenance
Companies that already trust me.
AI (Claude) training for the whole team and a custom MCP connected to their WooCommerce catalog.
Renewed the wine shop website and an AI assistant that recommends and answers customer questions.
Italian real-estate website in Next.js and an AWS migration — fast and ready to scale.
.NET ETL connecting client ERPs to their WMS, with AI-assisted client onboarding.
Custom MCP to connect their data with AI and automate internal queries.
An AI agent watching competitor pricing. Their verified-review portal (2026) was the pilot for Guestproof.
These services run through SANFELIU.
SANFELIU is the studio I founded and the trade name I work under: I sign invoices and contracts myself, as Joan Sanfeliu Vilarrasa. Here you get the summary; there, the catalogue, the cases and who is behind it.
If you are looking for a freelancer for one specific project: Freelance software engineer in Barcelona
Let's talk about your project.
The first conversation is free. If I can't help you, I'll tell you.