Adapters

A camera sees a plastic bottle, a dolphin, a car, or a suspicious object inside an X-ray scan. The business question is usually not philosophical. It is: can we adapt an existing vision model to this specific mess without retraining half the machine? That is where parameter-efficient fine-tuning sounds irresistible. Freeze most of the pretrained model. Add a small trainable module. Spend less money. Store fewer weights. Avoid turning every client dataset into a private bonfire of GPU time. Lovely. Procurement smiles. Engineers almost smile. ...

The adapter budget problem is not just training cost Budget is usually where fine-tuning conversations become less glamorous. A team wants a customized model. The engineer suggests LoRA because full fine-tuning is expensive. Everyone nods. Then the uncomfortable question arrives: which rank? A low rank is cheap but may underfit. A high rank may work better but costs more memory and inference compute. So the team trains several adapters, compares them, chooses one, and pretends the search process was a minor detail. It was not. It was the hidden invoice. ...