How to Use PyTorch Lightning Fabric for Distributed Training
A practical guide to PyTorch Lightning Fabric for ML engineers: how Fabric wraps DDP and FSDP boilerplate while keeping your training loop intact, migrating a plain PyTorch loop in 6 line changes, switching between single-GPU, DDP, FSDP, and multi-node strategies by changing one argument, gradient accumulation with no_backward_sync, gradient clipping with mixed precision handled automatically, distributed-safe checkpointing with fabric.save and fabric.load, and aggregating metrics across ranks with all_reduce.