Hi, I'm a developer working on a product that offers content creators and brands to create themes for making customizable prints on garments. We have a platform with tools for end users to design their own garments with these themes, and have so far also offered a checkout for end users to purchase said garments. We are now looking at Shopify mainly as a checkout/payment solution to replace the one we have. I've had a look at the app store and found some apps there that seem to satisfy our case, so I know its doable. However, since we need some integration with our platform, we need to develop the solution ourselves. The MVP of this would be for an end user to be redirected from our design tools/clients to a shopify store with a reference to the created design on our platform (preferably a view where images of the garment hosted by us are displayed) so that a purchase can be made with a resulting callback to our backend (we still manage stock keeping, fulfilment, and such on our end). The user should also be able to change product (garment) and product options (color, size, etc.). As I see it we need an app in place to at least manage some integration with our platform (importing products, order reporting, etc.), but here comes my question: does it make sense to make this app responsible of the whole solution? Is a theme powerful enough to handle all or some of the checkout/purchase part? Does it make sense use a theme for this? Should I be looking at custom storefronts? I struggle to understand the full extent of the different areas of concern for apps, themes, and storefronts. I would like to hear from you experienced developers if you see the obvious way to build this, or if I have misunderstood something. I'm gravitating towards just making one app to handle it all (if possible, it seems like it is exclusively rendered in the admin?) since that would seem to make the least cumbersome setup of a store for our customers.