What problem does it solve? Full fine-tuning of large language models (7B-70B) requires enormous GPU memory and produces multi-gigabyte checkpoints, making it impractical on consumer hardware. This Skill guides parameter-efficient fine-tuning with HuggingFace PEFT so you can train adapters of only a few megabytes while keeping the base model frozen. ## Core Features & Use Cases - LoRA and QLoRA workflows: Configure rank, alpha, dropout, and target modules, with 4-bit NF4 quantization via bitsandbytes to fit a 70B model on a single 24GB GPU. - 25+ PEFT methods: Includes AdaLoRA, IA3, Prefix Tuning, Prompt Tuning, DoRA, LoftQ, and rsLoRA with guidance on when each method fits. - Multi-adapter serving and merging: Load, switch, compose, and merge adapters at runtime, with integration patterns for TRL, Axolotl, and vLLM. - Use Case: Fine-tune Llama-3.1-8B on an instruction dataset with LoRA r=16, producing a 6MB adapter instead of a 16GB checkpoint, then merge it for deployment or serve multiple task adapters from one base model. ## Quick Start Ask the assistant to set up a LoRA fine-tuning script for your chosen base model and dataset, specifying rank, target modules, and whether to use 4-bit QLoRA quantization.