Case Studies

A real-estate viewing platform I built and launched working directly with the CEO, agents, photographers, and SEO specialists. I own it end to end: SSR performance, the audit-logged admin console, automated lead assignment for agents, floor-plan (図面) data extraction, infrastructure, and the bill, which I cut by 80%.

A travel eSIM commerce platform for visitors to Japan that I own end to end: checkout and payments, automated QR-code fulfillment, cross-domain authentication across the company's web properties, plus the competitor price intelligence that keeps plans priced right. I'm the final reviewer for every production release, and for six months I was the only engineer keeping it all running.

A Japanese-learning app for the JLPT N2 exam that I designed, built, shipped, and operate: spaced-repetition study system, Web Push reminders, passwordless auth (magic links + Google sign-in), and a furigana rendering engine I wrote because nothing off the shelf was good enough. It's free for JLPT learners, no ads, no paywall.

Production automation for a real-estate marketplace: a Claude-powered pipeline that scrapes listings, downloads 図面 floor-plan files, extracts structured data, notifies the team in Slack, and uploads results to the management site, replacing an entire manual workflow per listing with automation the team can audit.

A production FastAPI service that runs a brokerage's entire inbound-lead operation: Gmail and Meta lead-form ingestion, Claude-powered classification and field extraction, duplicate and returning-customer detection, round-robin agent assignment with day-off handling, interactive Slack approval, and Pipedrive CRM sync, with Google Sheets, the tool the team already trusted, as the single source of truth.

The backend for a new online travel agency product: I designed the architecture and the partner integration layer, reusable adapter patterns that make every external partner look the same to the core system, wrote the query-optimization guidelines the team adopted as standard, and onboarded and mentored the engineer building it with me.