Drop-day traffic was crashing their store. Every time.
Stackd — visual walkthrough available on request
Results
0
store outages in 6 drops since rebuild
140ms
time-to-interactive on product page (from 4.2s)
100%
of drop inventory sold within 12 minutes
TTI measured via Cloudflare Workers analytics and WebPageTest. Drop sell-through and outage data from Shopify Plus order reports. Load testing conducted via k6 at 50,000 concurrent sessions.
Situation
Stackd runs limited streetwear drops — 500 units, 20,000 concurrent users, sold out in 8 minutes when it works. Their Shopify Plus store was collapsing under load. Three consecutive drops had crashed at peak. They were losing sales and, worse, customer trust. The problem wasn't Shopify — it was the theme architecture, which was making 140 synchronous API calls on page load.
What we did
- 01
Performance audit tracing every network request on the product and cart pages
- 02
Rebuilt product page as a headless component — static shell, dynamic inventory via edge function
- 03
Custom queue system built in Cloudflare Workers to throttle checkout entry without error pages
- 04
Checkout experience rebuilt to pre-populate customer data via cookie for repeat buyers
- 05
Load tested to 50,000 concurrent sessions before the next drop
Tech stack
Technical audit
Findings from the pre-engagement audit. All resolved before handoff.
Walkthrough
Full build teardown and before/after demo
Video walkthrough
Full build teardown available on request
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