How does the B2C Commerce cartridge path work, and why does order matter?

The cartridge path is a colon-separated list of cartridge names configured in Business Manager under Administration > Sites > Manage Sites > [Site] > Settings. It controls how B2C Commerce resolves server-side scripts, ISML templates, and static files.

Resolution works left to right — the platform searches each cartridge from left to right until it finds the requested resource. The first match wins. A typical cartridge path looks like:

app_custom:plugin_wishlist:app_storefront_base:modules

Order matters because:

1. Custom cartridges must be to the LEFT of SFRA base cartridges so their overrides are discovered first
2. Plugin cartridges should come before the base but after the custom app cartridge
3. Shared utility cartridges (like modules) typically go last

If a cartridge is missing from the path entirely, its scripts and templates are invisible to the platform — this is a common cause of 404 errors during development.