A customer wants to self-host open-weights models instead of paying API fees. Model the real costs and make a recommendation.
The CFO sees API invoices; nobody sees the cost of the inference team they're about to hire. The strong answer models utilization, the variable that decides this question, and names the break-even honestly enough to be trusted.
Updated Aug 2026 · Grounded in real Forward Deployed Engineer interview loops and written to a senior-engineer editorial bar.
The CFO sees API invoices; nobody sees the cost of the inference team they're about to hire. The strong answer models utilization, the variable that decides this question, and names the break-even honestly enough to be trusted.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
