Case Study · Headless e-commerce
Treatsdom
A production headless storefront for a UK brand selling authentic Nigerian snacks to the diaspora — designed, built, deployed and operated end-to-end.
Overview
Treatsdom is a live, mobile-first storefront on a headless commerce backend. It runs a real Stripe checkout with digital wallets and SCA, a safety-critical allergen system, WCAG 2.1 AA accessibility, structured-data SEO and GDPR compliance — and cleared a full pre-launch security, accessibility and performance review with disaster recovery verified.
- Role
- Full-stack engineer — solo, end-to-end
- Scope
- Architecture → frontend → commerce backend → payments → DevOps → security → launch & ops
- Live
- treatsdom.com · mobile-first · GBP · UK delivery
Stack
What it does
A full store, not a demo
Headless architecture
A provider-swappable commerce layer with unified types — components consume the abstraction, never Medusa directly.
Server-authoritative money
Cart, pricing, discounts and delivery are computed on the server. The client never calculates a total.
Real Stripe checkout
Cards and digital wallets, a dedicated SCA challenge state, and the webhook as the single source of truth for payment.
Allergen safety system
Structured contains / may-contain / free-from data drives the card badge, PDP block, "free-from" filter and account profile — gated by a required-before-publish guard.
Combos & size grid
Fixed bundle products with live "you save" pricing, and three portion sizes across the range.
Lifecycle email
Order, dispatch and refund emails via Resend, with idempotency keys so nothing double-sends.
Engineering
Problems worth the write-up
Digital-wallet checkout that actually completes
Apple & Google Pay never fill the on-page form, so the flow hung on "processing". Reworked the Stripe Express Checkout Element to consume the wallet's own address and reconcile it with server-side flat-rate delivery — then hardened it through security and resilience review (no double-charge, no paid-but-no-order).
Surviving Safari's "liquid-glass" toolbar
The floating toolbar broke every full-screen overlay. Solved with viewport-fit: cover + safe-area insets + a ref-counted scroll-lock — after proving the obvious 100dvh fix was wrong and reverting it.
Rate limiting that fits the topology
All storefront traffic reaches the backend from Vercel's IPs, so per-IP limits put every customer in one bucket — eight sign-ins a minute site-wide. Re-keyed limits per account, with a separate IP ceiling.
A money-display bug inside the platform
Medusa's cart.subtotal quietly includes shipping, inflating the displayed subtotal and the free-delivery bar. Switched to an items-only basis so the cart, checkout and the promotion rule all agree.
Two production outages, diagnosed from outside
Traced and resolved a registrar WHOIS-verification suspension and a carrier-specific IP-reachability block — DNS forensics, not guesswork.
Outcomes
Shipped & verified
(order → webhook → capture → refund)
cards + 4 wallets
2 Critical + 10 High, all closed
+ Core Web Vitals budget
+ passing restore drill
our servers
Skills demonstrated
See it running.
Built by BLACKINS Creative Tech · 2026