TorchDynamo / torch.compile (Experimental)
TorchDynamo (Dynamo) is a Python-level JIT compiler designed to make unmodified PyTorch programs faster. It provides a clean API for compiler backends to hook in; its biggest feature is to dynamically modify Python bytecode just before execution. In the PyTorch/XLA 2.0 release, an experimental backend for Dynamo is provided for both inference and training. 
Dynamo provides a Torch FX (FX) graph when it recognizes a model pattern and PyTorch/XLA uses a Lazy Tensor approach to compile the FX graph and return the compiled function. To get more insight regarding the technical details about PyTorch/XLA’s dynamo implementation, check out this dev-discuss post and dynamo doc.