AI-powered Rails products, shipped by one senior engineer.

Production MVP in 4 to 6 weeks. Streaming LLM features, payments, admin, deploy. You own every line of code.

  • 8 yrs Rails
  • 4-domain platform in production
  • ex-Big Four audit
  • Spain, remote

Case study

IBICASA.com: a real estate marketplace, four domains, one codebase.

IBICASA is a live multi-tenant property marketplace for Ibiza. One Rails codebase serves the public portal, the admin panel, a partners REST API and a company portal, routed by hostname.

  • AI listing pipeline. Agents describe a property in chat; Claude responses stream over Action Cable into structured chip widgets, Google Maps geocodes the address, and background jobs write descriptions in English, Spanish and German.
  • Data you can trust. Property lifecycles modelled as explicit state machines, translatable content with custom concerns, policy-based authorisation throughout.
  • Owned end to end. Architecture, delivery and infrastructure by one engineer since 2025. Listing time for agents cut dramatically.
Visit ibicasa.com
IBICASA.com homepage
JazzPointIbiza.com

JazzPointIbiza.com

Ticketing platform for an international jazz festival at The Standard, Ibiza. Per-concert tickets with cart and checkout, instant e-tickets scanned at the door, a box-office cash register, hotel room booking and invoicing. Rails and Hotwire, live for the 2026 edition.

IbizaGardenHouses.com

IbizaGardenHouses.com

Production client site shipped in 2018 and still running: enquiry flows with Slack webhooks and automated email, built for a villa rental business.

Services

Three things I do very well.

Rails product builds

Multi-tenant apps, auth, payments, admin panels and Hotwire frontends. Boring, fast, maintainable. The stack that runs Shopify, GitHub and IBICASA.

AI features that ship

Claude and OpenAI integration, streaming UIs, tool use, structured outputs and background pipelines. Prompts and evals your team can maintain after I leave.

Fintech-grade backends

Six years as a financial auditor at PwC, Crowe Horwath and PKF Wallast. Audit trails, controls and precision are native to how I build, not learned on your project.

Process

No account managers. No handoffs.

  1. 01

    Call

    30 minutes, free. You explain the product, I ask the awkward questions.

  2. 02

    Proposal

    A scoped, priced proposal within 48 hours. Fixed price, fixed timeline.

  3. 03

    Build

    Weekly shipped demos on a staging URL. You see progress, not status reports.

  4. 04

    Handover

    Your repo, documentation, tests and deployment. No lock-in.

Pricing

Clear prices. One engineer, no agency overhead.

MVP Build

from €9,900

A production Rails app in 4 to 6 weeks. You own the code.

  • Auth, payments, admin and deploy
  • One AI-powered feature included
  • Weekly shipped demos on a staging URL
  • Tests, docs and handover
Start a project

AI Feature Sprint

from €4,500

Two weeks adding one AI-powered flow to your existing Rails app.

  • Streaming LLM UI over Hotwire
  • Background jobs and structured outputs
  • Claude or OpenAI, your choice
  • Prompt and eval setup you can maintain
Start a project

Fractional Engineer

€3,900 / month

Senior Rails and AI work, 2 days a week. Cancel monthly.

  • Roadmap, shipping and infra
  • Code review for your team
  • Direct Slack access
  • No long-term contract
Start a project

Prices exclude VAT. Larger scope quoted after the call.

Owen Moss

About

I'm Owen. The engineer on the call is the engineer in the code.

Eight years shipping production Rails, after six years auditing international clients at PwC, Crowe Horwath and PKF Wallast. Dutch and US citizen, based in Spain, working remotely with teams across Europe and the US.

I run IBICASA.com as sole engineer and build with AI-assisted tooling every day. Le Wagon AI Software Development bootcamp, 2025. Masters in Accountancy and Controlling, Groningen.

Working with one person means no handoffs, no account managers and no junior you never met. You get senior judgement from the first call to the last deploy.

Let's build it.

Send a short brief and you'll get a scoped, priced proposal within 48 hours. Or skip the form and grab a slot.

Book a 30 min call