PEFT (Parameter-Efficient Fine-Tuning) Fine-tune LLMs by training <1% of parameters using LoRA, QLoRA, and 25+ adapter methods. When to use PEFT Use PEFT/LoRA when: - Fine-tuning 7B-70B models on consumer GPUs (RTX 4090, A100) - Need to train <1% parameters (6MB adapters vs 14GB full model) - Want fast iteration with multiple task-specific adapters - Deploying multiple fine-tuned variants from one base model Use QLoRA (PEFT + quantization) when: - Fine-tuning 70B models on single 24GB GPU - Memory is the primary constraint - Can accept 5% quality trade-off vs full fine-tuning Use full fine-tu…