abuse

Spam detection is adversarial, imbalanced classification under a low-latency bar. The interviewer is watching for whether you set the threshold by cost asymmetry and lean on signals spammers cannot fake. Here is the design.

An attacker doesn't need to breach your LLM to hurt you, just make it do expensive work. A handful of crafted prompts can pin your GPUs and run up the bill. The defense is not a bigger rate limit.