Use Case · Core No. 2
PromptJIT
The self-cheapening AI runtime.
The Story
Every production AI system today shares one universal, slightly embarrassing property: the ten-thousandth request costs exactly as many tokens and exactly as much money as the first. The system never learns that it has seen this kind of request before. It pays full tuition for the same lesson, forever.
Java solved this problem decades ago. HotSpot made Java fast by noticing what runs often and compiling it down. PromptJIT makes AI cheap the same way — except what gets compiled is thought.
In PromptJIT, CLOUD_ADVANCED is the optimising
compiler, LOCAL is the CPU, and an autoboxing failure is
a deoptimisation trap. The cost of serving a request decays as a
function of how often the system has seen its kind — asymptotically
approaching local inference, and ultimately plain Java.
How It Is Built
The analogy is not decoration; it is a structural correspondence, and every component exists in PrOOPt today:
- The profiler — the plan cache with
PlanCacheStrategy.INTENTclusters requests by intent, not bytes, and its hit statistics reveal the hot paths of cognition. - The compiler — a
CLOUD_ADVANCEDfunction (with thinking enabled) studies successful traces of a hot intent and writes a rule-prompt that a small local model can follow. - The promotion gate — a deterministic
@CodeFunctionreplays the candidate rule against a golden set and promotes it only above a pass-rate threshold. - The deopt trap — if the local tier's output fails autoboxing or schema validation, the request falls back up the ladder and the rule goes back to the shop.
@PromptOrchestrator(
prompt = "Resolve the customer-operations request using registered tools.",
planMode = PlanMode.STATIC,
planCacheStrategy = PlanCacheStrategy.INTENT,
planCacheSize = 2000,
planCacheTtl = -1,
allowDynamic = true,
dynamicFunctionModel = ModelTier.CLOUD_FAST,
maxDynamicFunctions = 3
)
public Resolution handle(String request) { return null; }
public class PromptJitCompiler {
@PromptFunction(model = ModelTier.CLOUD_ADVANCED, thinking = true,
prompt = "You are an optimising compiler. For hot intent {profile}, "
+ "study these successful cloud-handled traces: {exemplars}. "
+ "Write a rule-prompt that a small local model can follow...")
public String compileRuleForLocal(IntentProfile profile, String exemplars,
String deoptCases) { return null; }
@CodeFunction(description = "Run the compiled rule against the golden "
+ "replay set on the LOCAL tier; promote only if pass-rate >= 0.98")
public PromotionVerdict verifyAndPromote(String candidateRule, String intent) { /* … */ }
}
Why It Is Unprecedented
Vendor prompt caching caches tokens. PromptJIT caches and
recompiles strategy — what to do, in what order, with which
tools, under which rules. Distillation transfers capability by
gradient descent over weeks; PromptJIT transfers it by writing
legible instructions in minutes — reviewable in a diff, reversible by
cache eviction. It is distillation without gradient descent, and the
cost-decay curve falls straight out of the audit log you were already
keeping. The endgame is lovely: when a compiled rule becomes stable
enough, it is a candidate for transcription into an actual
@CodeFunction. Cognition crystallises into software.
The Fine Print
The ladder's bottom rungs only fit recurring, structured work; genuinely novel and open-ended requests will live at cloud tiers forever, and that is fine — the promise is about the distribution's fat head. Compiled rules inherit the local model's ceiling, so the promotion gate, not optimism, decides what they carry. And intent drift is the moral equivalent of profile pollution: drift detection and evidence-based eviction are mandatory, not optional.
