Mitigating Catastrophic Forgetting via Experience Rehearsal & Parameter Freezing ensures that foundation models do not degrade in broad general intelligence, coding logic, or multi-lingual proficiency while fine-tuning on narrow domain datasets; core engineering strategies span: 1) Experience Rehearsal & Pre-training Data Mixing: co-mingling a 5%-20% ratio of high-entropy general instruction data (ShareGPT, GSM8k, code tokens) with domain samples to keep general neural representations active; 2) Parameter Isolation: utilizing PEFT/LoRA to freeze
>99% of original backbone weights, rendering foundational knowledge physically immutable; 3) Spherical Linear Interpolation (SLERP / Weight Merging): blending fine-tuned checkpoints with base models via
θmerged=(1−λ)θbase+λθsft to smoothen specialized parameters.