Compound AI Systems Optimization: A Survey of Methods, Challenges, and Future Directions

Yu-Ang Lee, Guan-Ting Yi, Mei-Yi Liu, Jui-Chao Lu, Guan-Bo Yang, Yun-Nung Chen


Abstract
Recent advancements in large language models (LLMs) and AI systems have led to a paradigm shift in the design and optimization of complex AI workflows. By integrating multiple components, compound AI systems have become increasingly adept at performing sophisticated tasks. However, as these systems grow in complexity, new challenges arise in optimizing not only individual components but also their interactions. While traditional optimization methods such as supervised fine-tuning (SFT) and reinforcement learning (RL) remain foundational, the rise of natural language feedback introduces promising new approaches, especially for optimizing non-differentiable systems. This paper provides a systematic review of recent progress in optimizing compound AI systems, encompassing both numerical and language-based techniques. We formalize the notion of compound AI system optimization, classify existing methods along several key dimensions, and highlight open research challenges and future directions in this rapidly evolving field.
Anthology ID:
2025.emnlp-main.1463
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
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Publisher:
Association for Computational Linguistics
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Pages:
28748–28763
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1463/
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Cite (ACL):
Yu-Ang Lee, Guan-Ting Yi, Mei-Yi Liu, Jui-Chao Lu, Guan-Bo Yang, and Yun-Nung Chen. 2025. Compound AI Systems Optimization: A Survey of Methods, Challenges, and Future Directions. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 28748–28763, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Compound AI Systems Optimization: A Survey of Methods, Challenges, and Future Directions (Lee et al., EMNLP 2025)
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