Composable commerce is about ditching one-size-fits-all platforms that slow you...

https://source-wiki.win/index.php/What_it_means_when_a_partner_%22owns%22_architecture_from_discovery_through_long-term_evolution

Composable commerce is about ditching one-size-fits-all platforms that slow you down. It lets you pick the best parts—payment, search, checkout—and swap them when needed without breaking everything