ProblemFrontier-model hardcoding and reactive fallbacks waste 60–75% of inference spend. Standard Python/SaaS routers add 65–180 ms of latency, making them unusable for inline execution.
LearningSequence-length profiling drove the architecture. Distillation to INT8 ONNX and JSON weights made sub-5 ms VPC deployment a reality, proving that HTTP header hygiene matters as much as model selection.
SolutionEngineered a bare-metal C++ proxy routing pipeline: 16-token WordPiece → INT8 ONNX embedding → 386-dim logistic regression → upstream JSON rewrite to guarantee a <5 ms routing SLA.
OutcomeAchieved 4.6 ms mean routing latency (14× faster than Python baselines). Delivered 75% fast-model eligibility and 67.8% holdout accuracy across a 10K prompt corpus.