Add the Skill, Keep the Answers
TL;DR for operators A model team can add coding capability to an existing assistant while still needing answers on established workloads to remain stable. ATLAS treats that as a joint release problem: reach the required coding performance while limiting how much the adapted model’s token predictions move from the frozen model on retained inputs. On Qwen3-8B with GSM8K retained, ATLAS has lower mean retained-output KL than every published baseline configuration tested at the same 13 MBPP+ score requirements, with reductions of 10.16% to 17.60%. ...