Amazon SageMaker adds training session APIs for custom LLM training loops
Amazon SageMaker AI introduced training session APIs that let developers write their own LLM training loops in Python while SageMaker handles GPU allocation, distributed execution, fault recovery and checkpointing. The APIs expose operations such as sample(), forward_backward() and optim_step() through ServiceClient, TrainingClient and SamplingClient, with billing per token processed. A companion cookbook provides SFT and RL recipes, and AWS reports a GRPO example on GSM8K raised held-out accura
Why it matters: It gives ML engineers and alignment researchers a concrete way to run custom SFT, RL and preference-optimization loops without provisioning or managing GPU infrastructure.