How do you do continued pretraining to adapt an LLM to a new domain without forgetting general ability?

Continued pretraining injects domain knowledge that fine-tuning cannot, but naively it wrecks general ability. The signal is the replay ratio, learning-rate rewarming, and how you measure forgetting.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.