The debate surrounding headless ecommerce has shifted from 'whether' to 'how'. In 2026, the primary point of friction for engineering teams is no longer the underlying API, but the reference architecture used to orchestrate it. For teams operating at scale, the choice usually narrows down to BigCommerce Catalyst and Shopify Hydrogen. Both frameworks have matured significantly, moving away from simple starter kits toward opinionated, enterprise-ready architectures. We have found that the decision