fine-tuning

Amazon Web Services has released agent-guided workflows in SageMaker AI that use AI coding agents to automate model customization. The feature includes nine pre-built skills covering use case definition, data preparation, fine-tuning technique selection (SFT, DPO, RLVR), evaluation, and deployment to Amazon Bedrock or SageMaker endpoints.

Amazon Bedrock now enables fine-tuning of Amazon Nova models using supervised fine-tuning (SFT), reinforcement fine-tuning (RFT), and model distillation. The service automates infrastructure provisioning and training orchestration, requiring only data upload to S3 and a single API call. Fine-tuned models run on-demand at standard inference pricing without provisioned capacity requirements.

Amazon Bedrock now supports Reinforcement Fine-Tuning (RFT) for customizing Amazon Nova and open source models using reward signals instead of labeled datasets. AWS reports up to 66% accuracy improvements over base models with reduced customization complexity. The approach works best for tasks with verifiable correctness (code, math) or subjective evaluation (moderation, summarization).

Google's Gemma 4 release marks a shift in open model strategy with Apache 2.0 licensing and competitive benchmarks, but real success depends on factors rarely measured: tooling stability, fine-tuning ease, and ecosystem adoption. The open model landscape is now crowded with alternatives like Qwen 3.5, Nemotron 3, and others—a maturation that changes what separates winners from the field.

Amazon Bedrock now enables reinforcement fine-tuning (RFT) across multiple model families including Amazon Nova, open-weight models like OpenAI's GPT-OSS 20B, and Qwen 3 32B. The service automates the end-to-end customization workflow using GRPO optimization, allowing models to learn from feedback on multiple responses rather than static training datasets, with support for OpenAI-compatible APIs.