Axolotl — Config-Driven Production Fine-Tuning
Axolotl is the declarative, multi-GPU production path for fine-tuning. One YAML config describes the entire run — model, data, PEFT, distributed strategy, eval — and underneath, it is still TRL's trainers. The config-as-source-of-truth pattern is why practitioners reach for Axolotl when the job is real, multi-GPU, and must reproduce.
Axolotl wraps TRL. Underneath the YAML is still SFTTrainer / DPOTrainer / GRPOTrainer. Axolotl's value is the declarative config layer, opinionated cross-family defaults, and battle-tested multi-GPU orchestration (FSDP / DeepSpeed) that is fiddly and error-prone to write by hand.
The YAML config is the source of truth. Model, dataset, PEFT settings, hyperparameters, distributed strategy, and eval are all one declarative file. This makes runs reproducible, diff-able, and CI-validatable — the property that matters most in production.
Axolotl owns the multi-GPU story. This is the decisive difference from Unsloth (single-GPU speed). When a job spans 2, 4, or 8 GPUs on a 70B model, Axolotl's curated FSDP/DeepSpeed configs are the path of least resistance; Unsloth's multi-GPU support is limited and OOM-prone.
Choose by the constraint: Axolotl for production/multi-GPU/reproducibility, Unsloth for single-GPU speed, raw TRL for full control. Axolotl is preferred by practitioners for 'real' multi-GPU configs because it removes the DeepSpeed/FSDP configuration tax that raw TRL makes you pay yourself.