AJ Villalobos.

Senior Ruby on Rails Engineer

I have spent twelve years building production Rails applications for fintech, healthtech, and SaaS teams in the US, UK, and Australia. These days I pair that experience with AI-assisted development, using Claude Code, agentic loops, and parallel agents without lowering the bar for what reaches production.

Work

2025–now

Lavanda

Senior Ruby on Rails Developer · UK, remote

I build features for a property management and bookings platform used by build-to-rent and co-living operators (Rails, GraphQL, Next.js). Recent work includes the DocuSign lease-signing integration and booking-import tooling for onboarding new clients. Day to day I lean on Claude Code: custom skills, self-verifying agent loops, and parallel agents in git worktrees.

2024–25

ShiftCare

Ruby on Rails Engineer · Sydney, Australia

Shipped customer-facing and internal features for an aged-care platform, Rails APIs with a Vue frontend, balancing usability with maintainable backend architecture.

2023–24

Radiopaedia

Ruby on Rails Developer · Australia

Improved mobile UX and key page layouts for one of the largest radiology references on the web, TypeScript and Preact components inside a Rails app.

2019–23

Kangarootime

Ruby on Rails Developer · United States

Maintained and extended a legacy childcare-center platform used across the US. Refactored its core status-tracking model and built COVID screening and onboarding features during a high-change period.

2017–20

BloomSolutions

Software Engineer · Makati, Philippines

Built features for BloomRemit, a cryptocurrency-enabled remittance platform that facilitated over $120M in customer transactions, with an emphasis on tested, maintainable service patterns.

2014–18

Earlier

POS integrations and a Messenger bot at Tanda, booking platforms and private gems at Aelogica, Rails and Ember work at Proudcloud, and Rails features at YouSource. Full history in the PDF resume.

Projects

Brand

Arqen.dev

The home of my self-funded products: software that actually works for Philippine businesses, built with firsthand knowledge of local compliance rather than theoretical knowledge. The three products below ship under it.

Inventory

KeepTrack.ph

Inventory management for Philippine small businesses: real-time stock tracking, expiry alerts, purchase orders and supplier management, and recipe costing for restaurants, pharmacies, and retail. Tagline: stop guessing what’s in stock.

Payroll

Timekeep.ph

Payroll, attendance, and scheduling for Philippine SMEs. One-click payroll with SSS, PhilHealth, Pag-IBIG, and withholding tax computed automatically, plus a facial-verification attendance kiosk and an employee self-service portal.

Healthtech

SigRx.app

A digital prescription pad for Philippine doctors. Prescriptions formatted for standard pad sizes, patient records, a pre-loaded medicine library, and medical certificates on matching letterhead. Currently in private beta.

Acquired

Privacy-first link shortener

A simple Bitly alternative built for GDPR compliance. Launched as a paid product and later acquired by one of its early users.

Open source

Clover Ruby gem

A Ruby wrapper for the Clover POS REST API. Archived, then forked and used in other teams’ production integrations.

Resume

PDF

Hiring or screening? The resume has the full work history, education, and contact details in a printable page.

Download the resume (PDF) ↓