Tay L.

I build and scale multi-tenant Ruby on Rails SaaS, and I take over Rails apps that other developers left behind. Most Rails apps break in the same place. The app runs fine for 10 customers, then falls apart at 100. Data leaks between tenants. Background jobs pile up. Every new client needs manual setup. Fixing this later costs more than building it right the first time. That is the work I do. WHAT I BUILD 1. Multi-tenant SaaS - Tenant isolation at database level, so customer data never crosses - Self-serve onboarding, so you stop creating accounts by hand - Roles and permissions that still work after you add new plans 2. APIs and integrations - GraphQL and REST APIs your mobile or frontend team can build against - OAuth integrations with third-party providers (Google, Fitbit, review and payment platforms) - Webhooks and sync jobs that retry instead of failing silently - Sidekiq pipelines for imports, reports, notifications, scheduled work 3. AI features that survive production - LLM tool-calling, where the model calls your real Rails services with proper validation and error handling - Agent workflows running in background jobs, with retries and cost limits - RAG over your own data, with source citation - Built as a normal service in your app, with tests, logs and a cost ceiling. Your team can maintain it after I leave. 4. Rails rescue and takeover - You have a Rails app, the developer is gone, nobody knows how it works - I run the app like a real user first, map the business flows your revenue depends on, then start shipping. No two-week audit document - Rails and gem upgrades one safe step at a time, tests around the flows that matter, slow queries and silent job failures fixed - Short written handover at the end, in plain English HOW I WORK You define the outcome. I handle the rest: diagnose, build, test, deploy, document. No hand-holding needed. All work is done by me. Nothing is outsourced. I ship to production, not to a demo branch. Tests and migration notes included. I also run my own Rails SaaS products, so I make decisions like an owner, not like a ticket taker. GOOD FIT IF - You have a Rails app that must serve many customers from one codebase - You inherited a Rails codebase and need someone to own it - You want to add AI to a real product, not build another demo - You want a senior Rails developer long term, not a one-week patch NOT A FIT IF - You need WordPress, PHP, or the cheapest bid - You want someone to follow tickets without asking why Send me your repo or your spec. I will reply with what I would fix first and how long it takes.