For ecommerce brands in 2026, the storefront frontend is no longer a styling exercise — it is the single largest conversion lever left to pull. Three approaches now compete for every new build: AI-generated frontends (produced from a prompt by tools like Sketchflow.ai, Lovable, or Builder.io), hand-coded frontends (built by an engineering team in Next.js, Shopify Hydrogen, or bespoke React), and template-based frontends (Shopify themes, Webflow templates, or pre-built ecommerce builders). The question has stopped being "which one is fastest to ship" — they are all fast now. The question is which one actually converts. This guide compares the three approaches head-to-head on the metrics that move revenue: Core Web Vitals, mobile UX, iteration speed, personalization, and code ownership — and names which approach wins for which stage of an ecommerce business.…