Every whole-product conversation starts with integration. APIs, connectors, the joint architecture diagram, a slide with two logos and an arrow between them.
The question that decides whether any of it is real comes later, and it’s duller. Who sends the invoice?
You would expect that to be where these things fall apart — three companies, one customer, and a line item nobody wants to own. Mostly it isn’t. In most partnership discussions it gets settled between the partners without much drama, and how it gets settled is the part worth noticing. One partner ends up carrying the paper: the contract with the customer, the legal framework, the thing procurement actually signs.
That is an advantage rather than an overhead. Only one party has to put that framework in place. The customer buys one thing, from one company, on one invoice, and the rings behind it stay the suppliers’ problem instead of becoming theirs.
Which is worth remembering when you are the partner not holding the paper. You are not being cut out of the deal. You are being spared the half of it that scales worst.