Commerce · Shipped for a client
Hosted commerce: Shopify runs the checkout, the payment compliance and the uptime; the theme and the data model are yours.
The argument for hosted commerce is not that it is easier. It is that card handling, fraud and checkout uptime are somebody's full-time job, and on a store doing real volume that somebody should not be a contractor you can lose.
01
The checkout is the one surface where a bug is measured in refunds rather than in bug reports. Shopify carries it, along with the compliance that comes attached to card data, and neither is work a client should be paying us to re-invent.
02
Themes are written rather than assembled. The default theme is where a store looks like every other store, and it is also where the structured data for products is thinnest — both are fixed in the same pass.
03
It has a real export. A platform you cannot leave is a platform that has stopped competing for the business, and we check the exit before recommending the entrance.
An entry that cannot point at something you can open, run or read does not compile. That is a property of the type, not a promise in a paragraph.
Invariant
Shopify owns the checkout, which means it also owns what the checkout can be asked to do. Unusual pricing logic, multi-party settlement or an order model that is not really an order all fight the platform, and past a certain point the honest answer is that the business needs its own transactional system rather than a better theme.