Model serving and inference engines

The South City kitchen was divided into the stove room and the front hall. Old Qian managed the stove room and knew the maximum heat of each stove, whether it was suited to stewing or stir-frying, and how much hotter it got after burning continuously for two hours.

Old Zhou managed front-of-house scheduling, deciding which order goes first, which dish goes to which stove, and whether to borrow the neighbor's when stoves are short. He didn't dismantle stoves or study firewood; he only managed shifts and delivery.

A restaurant chain once complained that the taste was sometimes good and sometimes bad. Old Zhou checked the scheduling, and every order was delivered to the stove on time; Old Qian checked the heat, and every stove was fully lit. The two sat facing each other for a long time before realizing that slow-cooked dishes had been assigned to the quick-fry stove.

The stove was not broken, but the scheduling assigned the wrong targets. What was worse, one stove's heat dissipation worsened after continuous work, and Lao Zhou did not know, still piling on orders during peak hours; the dishes did not report errors, but became more and more undercooked.

They built an interface layer. The kitchen posted the current temperature, how much longer it could hold, and what dishes it suited on a board; the front of house assigned orders based on these signals. The kitchen didn't need to understand the whole menu, and the front of house didn't need to take apart the stove.

Later, the kitchen rented stoves made by different manufacturers—some heated fast, some held temperature steadily, some saved firewood but started slowly. As long as each stove clearly reported its state, the front hall could match orders accordingly. The kitchen finally drew the line: one side was responsible for getting the fire right, the other for dispatching orders properly, and the signal line in between was worth a year's worth of ingredient waste.

The apprentice later asked why Old Qian wasn't also put on scheduling, or Old Zhou put on fire control. Old Qian said the kitchen needs to understand physical limits, the front hall needs to understand order commitments; mixing them together means no one stays focused.

What they truly shared was signals. The temperature board, shift book, anomaly bell, and backup stove list let the two roles understand each other's boundaries. The larger the kitchen expanded, the more valuable this dividing line became; only after distinguishing them could they know whether to repair the stove or change the schedule. Later, when newcomers started, the old master no longer began with abstract labels, but had them review that failure: where intuition had originally been relied on, why the first patch was not enough, and how the new arrangement kept risk in a place that could be checked. Only when they could explain these details clearly, and also point out when to continue using it and when to upgrade it, did they truly understand this approach. Later they also handed this approach to newcomers for practice: first have newcomers do it the old way and see how errors appear; then redo it under the new rules and see which step was blocked in advance and which step left evidence. If newcomers could only recite names, they would still misuse it in similar scenarios; only those who could state the applicable boundaries, costs, and remedies after failure were allowed to take work independently.