Introduction: Understanding the Core Challenges of Weight LoadingBefore diving into vLLM's weight loading implementation, it's essential to first understand the fundamental problems it aims to solve. Large language model weights are typically stored on disk as checkpoint files. The weight loading task involves taking the tensors from these files and correctly populating every parameter in the model's inference code. While this might seem straightforward—read files, match by name, copy data—three critical challenges make this process signific...