Data Engineering SFT: NEFTune & SemDeDup | SLM Playbook

← Series hub ← Previous | Next → In the era of LLMs/SLMs, the classic data science proverb: “Garbage In, Garbage Out” has never been more relevant. When performing Supervised Fine-Tuning (SFT) for Small Language Models (SLMs), data quality and format dictate over 90% of the model’s downstream capabilities. Feeding millions of raw, web-scraped dialogue pairs or low-quality synthetic data directly into your model will overfit it to repetitive phrasing, restrict its reasoning capabilities, and waste thousands of GPU hours. ...

May 22, 2026 · 7 min · Lê Tuấn Anh

Practical QLoRA Fine-tuning: Axolotl & Unsloth | SLM Playbook

QLoRA fine-tuning lets you adapt a multi-billion parameter model on a single consumer GPU — like an RTX 3090 or A10G — by combining LoRA adapter training with 4-bit NF4 quantization. This article covers the math, a production Axolotl YAML config, and Unsloth integration for 3x training speedup. ← Series hub ← Previous | Next → 1. LoRA: Low-Rank Adaptation Matrix Decomposition LoRA reduces fine-tuning cost by freezing all original model weights and training only two small adapter matrices (A and B) of rank r — typically 8–64. This cuts trainable parameters by over 99% versus full fine-tuning with near-zero performance loss. ...

May 23, 2026 · 8 min · Lê Tuấn Anh