Coastal Threads
+12% mobile conversion in 90 days
A fashion brand on a stale OS 1.0 theme — slow on mobile with too many third-party scripts. We rebuilt the storefront on Shopify OS 2.0 with critical CSS, image optimization, and a redesigned product page.
The Challenge
Coastal Threads' theme was 4 years old with 8 active third-party apps weighing on mobile performance. Lighthouse mobile sat between 32-40 and bounce rate was 64%. They wanted a rebuild without losing 2 years of SEO equity, with a 6-week timeline before their spring product drop.
The Solution
We rebuilt the theme on OS 2.0 with a custom design system. Critical CSS inlined for the above-the-fold hero, all third-party scripts deferred (chat, reviews, analytics), jQuery-heavy interactivity replaced with Alpine.js. Product images converted to WebP with AVIF fallback and a responsive srcset. PDP got a fresh layout with sticky add-to-cart on mobile.
What we shipped
- Custom Shopify theme (OS 2.0)
- Core Web Vitals optimization
- Product detail page redesign
- Cart drawer + checkout polish
Tech stack
Results — measured
| Metric | Before | After |
|---|---|---|
| Mobile Lighthouse score | 38 | 76 |
| Mobile conversion rate | 0.94% | 1.05% |
| Largest Contentful Paint (LCP) | 4.6s | 2.2s |
| Mobile bounce rate | 64% | 56% |
| Average Order Value | $54 | $61 |
"Xpertshire rebuilt our Shopify theme over 6 weeks. Lighthouse mobile moved from 38 to 76, and we saw a measurable lift in mobile conversion within the first quarter. Communication was clear, deadlines held, scope didn't drift."
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