mqa gqa

MQA and GQA cut the KV cache by sharing key/value heads. MLA goes another way: compress K and V into a low-rank latent and cache that instead. What matters is recognizing it as a cache trick rather than a head-sharing trick, and why it preserves quality.

The KV cache is what makes LLM serving hard, and the interviewer wants the mechanics: what it holds, why it caps concurrency, and the tricks that shrink it. This is the answer that shows you grasp decode-time economics.