LLM-FE: Automated Feature Engineering for Tabular Data with LLMs as Evolutionary Optimizers

TMLR Paper6925 Authors

08 Jan 2026 (modified: 17 Jan 2026)Under review for TMLREveryoneRevisionsBibTeXCC BY 4.0
Abstract: Automated feature engineering plays a critical role in improving predictive model performance for tabular learning tasks. Traditional automated feature engineering methods are limited by their reliance on pre-defined transformations within fixed, manually designed search spaces, often neglecting domain knowledge. Recent advances using Large Language Models (LLMs) have enabled the integration of domain knowledge into the feature engineering process. However, existing LLM-based approaches use direct prompting or rely solely on validation scores for feature selection, failing to leverage insights from prior feature discovery experiments or establish meaningful reasoning between feature generation and data-driven performance. To address these challenges, we propose LLM-FE, a novel framework that combines evolutionary search with the domain knowledge and reasoning capabilities of LLMs to automatically discover effective features for tabular learning tasks. LLM-FE formulates feature engineering as a program search problem, where LLMs propose new feature transformation programs iteratively, and data-driven feedback guides the search process. Our results demonstrate that LLM-FE consistently outperforms state-of-the-art baselines, showcasing generalizability across diverse models, tasks, and datasets.
Submission Type: Regular submission (no more than 12 pages of main content)
Assigned Action Editor: ~Xi_Lin2
Submission Number: 6925
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