How to Answer
“First I find out what ‘no data leaving’ actually means to them, because there are three versions and they differ by an order of magnitude in cost. One: nothing goes to a new third party — a managed model endpoint inside the cloud region and tenancy they already use is fine. Two: nothing leaves their VPC — now I’m self-hosting open weights on GPUs in that VPC. Three: air-gapped. That last one is a different product.
Assume version two. The real cost is that I lose the frontier model, and that shows up as a quality regression rather than an outage — which is exactly the kind of thing nobody notices for a month. So the first artefact I build is an eval set against the current system, before we migrate, so the delta is a number we agreed on instead of a complaint in month three.
Then the unglamorous half: who runs those GPUs, who patches them, who is awake at 3am. Self-hosting is an operating commitment, not a deployment step.”