APEX: Automated Prompt Engineering eXpert with Dynamic Data Selection

In three linesAPEX automatically optimizes prompts by dynamically selecting training data. The framework stratifies the dataset into Easy, Hard, and Mixed tiers, prioritizing the Mixed frontier to generate informative mutations. Within 5,000 evaluation calls, APEX improves performance by 11.2% on Gemini 2.5 Flash and 6.8% on Gemma 3 27B.

Summary generated by Claude — human-verified