Iurii Uses: #Payments

Pikkuna — E-commerce for Vinyl Curtains & PVC Products

International e-commerce platform with 30 locales, product configurators, AI chatbot, and fully automated order flow: Stripe → Zoho CRM → Airtable → Mailgun →

Prevent overselling under concurrent checkouts: reservations vs hard decrements, SELECT FOR UPDATE, deadlock-safe multi-line carts, and the payment window.

Subscription billing edge cases Stripe glosses over: proration, dunning, the state machine, cancellation timing, refunds, VAT, and webhook ordering.

Stripe to Mollie migration in production: mandates instead of Subscriptions, thin webhooks, no proration, no portal, no Tax. What you rebuild yourself.

Production transactional emails with React Email and Resend: PDF invoice generation via react-pdf, Vercel Blob temporary storage, and BullMQ Stripe webhook

E-commerce order automation that cut 160+ hours/month of manual work to zero: Stripe webhook to VAT invoice and tracking in under 2 minutes.

Stripe webhook production architecture: idempotency keys in PostgreSQL and Redis, BullMQ queue, signature verification in Next.js App Router — with full