Same Shop, Second Engine: One Design on WooCommerce and OpenCart

The same furniture shop as the WooCommerce stand next door — same layout, same 420-product feed, same catalogue tree, same texts — rebuilt on OpenCart 4.1. Both are live, both admin panels are open to guests, and a comparison page puts them side by side with numbers taken by one instrument in one sitting. This answers the question a client asks first: will it work on my platform? The design carried over unchanged. The engine did not. OpenCart 4.1 has no second theme at the file level, so the theme lives as an extension and swaps templates on an event — no core file is touched, and an update will not wipe the work. A product URL needs an explicit route segment or it silently returns 200 and shows the home page. Image resizing cannot read SVG at all. A cache miss returns an empty array instead of false, so an is_array() check passes and the page comes out blank without an error. Checkout is five separate endpoints where the shipping list must be requested before it can be chosen. Every one of those breaks the storefront silently. What the stand does not do: no money moves, payment is cash on delivery, product images are generated from dimensions rather than photographed, and data resets every 6 hours. Guest admin: shop-oc.devs-code.site/keruvannya, demo / demo.

• One design, two engines — click through both admin panels and compare
• Comparison page with honest numbers: both stands measured by one instrument, same hour
• PageSpeed 99–100 on mobile, CLS 0.000 — no jQuery, no Bootstrap, 230 KB the theme never used
• Theme as an extension: not one core file modified, so updates survive
• Nova Poshta branch lookup live from the carrier's public API during checkout
• A monitor places a full order every 5 minutes and removes it afterwards