When Gradients Collide: Failure Modes of Multi-Objective Prompt Optimization for LLM Judges
Researchers identify critical failure modes in multi-objective prompt optimization for LLM judges, finding that jointly optimizing across multiple evaluation criteria reduces gradient task-focus by 59% and combining single-objective prompts degrades performance by 27%. The study reveals fundamental limitations in extending textual gradient methods to multi-criteria scenarios, constraining practical applications of automated LLM judge customization.