Shopify Theme Developer for Full Site Overhaul (Performance + Conversion)

We run paid social and search for an established children's book brand on Shopify. The ads are working. Click-through rate is strong and we're sending qualified, motivated traffic to the site. The problem is what happens after the click. The site converts at a fraction of where it should, and the data points to the storefront itself, not the traffic. We need a Shopify theme developer to take ownership of a full overhaul covering performance, theme structure, and on-page conversion. This is one role owning the whole site, not a narrow technical patch. Here's what we're working with: Mobile PageSpeed score in the low teens, with LCP near 15 seconds and significant layout shift Close to 300 page requests, which points to heavy app bloat that needs auditing and trimming A portion of inbound traffic hitting 404 errors on entry Product page layout problems, including an upsell widget that buries the primary purchase action No review or social proof structure anywhere on the product pages Navigation and pricing inconsistencies across page templates We've already done the diagnostic and CRO work, so you'll be building against a clear scope rather than guessing at priorities. We direct the strategy. You own the build. What we're looking for: Demonstrated Shopify theme development experience specifically, working in Liquid, HTML, CSS, and JS A track record you can point to with before-and-after performance numbers, not just screenshots A habit of working on a duplicate or development theme so the live store stays safe Comfort being directed by a marketing team and communicating in outcomes, like load time and conversion impact, rather than ticket-by-ticket To apply, answer this before quoting: based on the symptoms above, what's the first thing you'd want to check on the store, and why? We're more interested in how you think about the problem than in a fast price.