Ecdysis: fix the harness only for failure patterns that recur across tasks, not for each single failure

arXiv 2609.11677·medium signalXBlueskyLinkedInCopy link

Harness self-evolution methods that revise against individual failures overfit and end up accommodating one model's quirks. Ecdysis aggregates failure evidence across a batch of task instances, and a multi-role diagnosis step separates model-specific deficiencies from systematic harness ones before it edits the harness spec. It reports 1.84x faster harness training and 18.56% higher reasoning accuracy than existing harness-evolution methods. For any self-improving pipeline, the takeaway is to batch failure analysis and require a pattern to show up across tasks before you change a prompt or tool.