MOST PEOPLE ASSUME SLOW LLM INFERENCE MEANS THEY NEED A BIGGER GPU. Often it means they are running the wrong inference engine. Naive serving reserves worst-case memory for every single request, and that assumption alone burns 60 to 80% of your GPU memory before you have processed anything. vLLM's PagedAttention allocates memory in fixed pages, on demand, the same idea operating systems use for virtual memory. Utilization jumps to roughly 95%. This walkthrough goes from that concept straight into a production OpenAI-compatible server, load testing, and a real monitoring dashboard, not just the theory.(CyrilXBT)