I'm planning on launching an eCommerce start-up in the next couple of months; I have been building out our minimum viable product, which has to be (I think at-least) hosted separately from Shopify because it involves a very custom editor which involves storing user images, running custom machine-learning algorithms to modify user input data, etc. Right now I am hosting on a Heroku + AWS combination.
At this point I have the site working such that the user can go to the homepage, create an account, and use our customized editor to make their POD product. I now want to allow the user to be able to buy their product that they created through a checkout system and once the order is completed, to have it automatically sent to my POD supplier (they have an API and Shopfiy plugin). Ideally, I would also like the users to also be able to sell their work they created with my site on a marketplace, where they would take a cut of the profits.
Is this something that I can use Shopify for, or should I continue programming from scratch and implement an entire checkout + order management + affiliate system (please don't say this lol)? I would very much appreciate any resources or advice you could give me in managing this development.