Description

I'm Mario, partner at Laboratorio Web (laboratorioweb.es), a small studio with two products in production: TalentoHQ (talentohq.com), an HR platform since 2022 and OfiHQ (ofihq.com), a business operations suite since 2025. Across both I've shipped most of what a business needs to operate: CRM, invoicing, time tracking, HR, projects, document signing, surveys, recruiting, and more.

Here's where I can help you.

Custom software in Rails. If you need a backend, an internal tool, or a SaaS built from scratch, that's what I do every day. Part of that work is taking processes still running on paper, spreadsheets, or email and turning them into software people actually use.

AI integration. I've added several AI features to OfiHQ and TalentoHQ. The central piece is a chatbot that doesn't just answer, it creates, edits, and acts on real-time data: from a single message someone can generate an invoice, schedule a meeting, advance a project, or pull a weekly summary of their team's performance. I've also added smaller integrations where AI saves real time: photos of receipts that turn into structured expenses, contract templates generated from a PDF, weekly digests with the insights that matter. I can build the same kind of integration into your product.

Verifactu compliance. Spain's new e-invoicing regulation requires every invoice to be cryptographically signed, registered with the AEAT (Spanish tax agency), and chained in a tamper-evident sequence. I built our full invoicing module from scratch and made it Verifactu compliant: XAdES signing, hash chain with database locking, SOAP integration with AEAT, QR codes, rectifications. If your Rails app needs to comply, I can plug it in.

I'm based in Logroño. I write about what I build at mario.alvareznavarro.es. If any of this fits what you're working on, happy to chat.

Industry field of expertise

Languages

Spanish
Native or bilingual
English
Fluent

Workplace preferences

Remote only

Primarily works remotely

De pura Cepa, Sociedad Gastronómica
Freelance Software Developer
SOFTWARE PUBLISHING
September 2024 - Today (1 year and 9 months)
Logroño, Spain
Designed and built a resource booking system for a private members' club in Logroño. Sole developer end-to-end: requirements gathering with the client, development, deployment, and ongoing production maintenance.
Live and in daily use for months with no significant incidents.
Ruby on Rails Ruby Software Development Fullstack End-to-End Project Delivery
Laboratorio Web
Partner & Software Developer
SOFTWARE PUBLISHING
October 2023 - Today (2 years and 8 months)
Logroño, Spain
Lead the technical direction of OfiHQ and a core contributor on TalentoHQ. Own a significant share of the architecture across both products and authored most of OfiHQ's critical modules over the last year.
Designed and own the platform layer that powers both SaaS: multi-tenant data model, in-house permissions and visibility engine built from scratch, declarative approval engine, custom fields, universal audit trail, route translation across 5 languages.
Built and shipped a wide product surface: the AI assistant with multi-provider chat and per-role tool calls, our own MCP server with OAuth, the Verifactu compliance module integrated with AEAT, a public REST API v3 with OAuth, and most of the business modules: invoicing, CRM, HR, ATS, performance, training, projects, expenses, purchases, document signing, bookings, payroll.
Direct line to the paying customers of both products: discovery, demos, technical onboarding, ongoing support, and the feedback loop that drives the roadmap.
Own the infrastructure (Kamal multi-host deploys to Hetzner, Postgres, Sidekiq) and the engineering discipline behind both codebases (roughly 1:1 ratio of test code to production code, ~1,200 test files per product).
Ruby on Rails PostgreSQL AI Integration B2B SaaS Fullstack