Dong H.

7+ years building Rails marketplaces, SaaS and customer-facing apps, from database to UI. 3,300+ hours on Upwork Recent work: • Multi-channel customer support inbox (Rails + Vue): WhatsApp bulk campaigns with delivery tracking, Gmail/Microsoft Graph email, role-based permissions, full RTL support • Remote patient monitoring platform for pharmacies & clinics (Rails + React): action-queue dashboard, questionnaire engine, medical claim submission • Community marketplace with Stripe Connect: auctions, rentals with held deposits, split payments, disputes • Shopify app that sends automated postcard campaigns with monthly subscriptions What I can help with: • New Rails apps and MVPs (Rails 7/8, Hotwire, React or Vue) • Payments: Stripe, Stripe Connect, subscriptions, marketplace payouts • Taking over and improving existing/legacy Rails codebases, Rails upgrades • APIs & integrations: Shopify, WhatsApp, Gmail/Outlook, OAuth • Background jobs, real-time features (Sidekiq, Action Cable), PostgreSQL performance • Deployment on AWS, Heroku, Docker; RSpec test coverage How I work: clear written updates, small reviewable PRs, and I confirm requirements in writing before building so nothing gets lost. Available for overlap with US/EU hours. Send me your project or codebase - I'll reply with how I'd approach it.