Senior Developer and Tech & AI Lead in Astorga (León), Spain
Javier González Estarriol
I build the software that runs a warehouse and an online store, from order to truck.
I write software and lead technology and AI projects. I enjoy building systems that solve real business problems: integrations, automation and data. Since November 2023 I've been doing that at an online fragrance brand with its own factory, where I look after the WMS, carrier integrations, RFID traceability, shop-floor automation and the servers it all runs on.
Now Connecting a vertical lift module to the WMS and getting ready for Black Friday.
In numbers
- Average order-prep time, 2025 → 2026
- −90%
- Logistics cost as a share of sales
- −24%
- Orders fulfilled with our own WMS
- 99.9%
- Automated tests in the ERP
- ~1,560
- Commits to the main repository in 2026 that are mine
- 95%
Lab
Projects
- Our own WMS on top of pick-to-light 90% faster order prep, 99.9% of orders fulfilled
- End-to-end RFID traceability RFID-verified pallets since March 2026
- A robot arm that loads cartridges without mistakes Two machines in parallel, no manual scanning
- Carriers and cost control Logistics cost as a share of sales, down 24%
- Post-sale without third-party platforms In-house tracking and returns, no platform fees
- A vertical lift module and my own simulator 1,225 slots driven by the WMS
- An AI assistant that can't break anything Read-only by design, with 55 tests
Experience
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Senior Developer · Tech & AI Innovation Lead Online fragrance brand with its own factory
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Senior Developer Same company
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Junior Developer Same company
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Freelance Full-Stack Developer Investment holding (client)
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Supervisor Grupo Dani García (restaurants)
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Chef de Rang Grupo Dani García (restaurants)
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Waiter, alongside freelance web development Casa Maragata
Education
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Full-Stack Development Bootcamp ISDI Coders
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Higher Technician Diploma in Multiplatform App Development (DAM) CFP María Auxiliadora
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Computer Engineering (not completed) University of León
Languages
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Spanish
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English
Tools
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Backend Python, Flask, SQLAlchemy, Node.js, Express
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Data PostgreSQL, MongoDB, Redis, Supabase
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Infrastructure AWS EC2, Linux, nginx, Docker, PM2, GitHub Actions
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Integrations Shopify, GLS, SEUR, UPS, Correos Express
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Warehouse UHF RFID (SGTIN-96), wearable scanners, pick-to-light, vertical lift module, robot arm, sorter, ZPL
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AI tool-calling LLMs, Cursor, Claude Code
How I work
I use AI agents every day, but what decides whether something is right is tests, CI and production data. I'd rather validate in code than write an instruction in a PDF, and I always leave a way back.
Before moving into tech I spent almost ten years in hospitality, the last ones leading dining-room teams. That's where my obsession with tools that work for people in a hurry comes from.