Optimus: A Generic Operator-Level PyTorch Model Transformation Framework

Menglu Yu; Jiaqi Xu; Yuzhen Huang; Yanbo Liang; Jia Liu; Shuai Yang; Jason Ansel; Elias Ellison; Edward Yang; Brian Hirsh; Jia Chen Ren; Will Feng; Oguz Ulgen; Xu Zhao; Daohang Shi; Huaqing Xiong; Quanyu Zhu; Mingming Ding; Junqing Zhou; Ruilin Chen; Yuhang Yang; Chi-Keung Luk

arXiv · 2607.02945

Optimus: A Generic Operator-Level PyTorch Model Transformation Framework

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Abstract

In large-scale industrial applications, deep learning models that power recommendation and ranking have complex and diverse model architectures. These models are continuously developed and refined by large teams of machine learning engineers, rendering manual optimization infeasible. Consequently, graph-based optimization techniques have become an industry standard for boosting performance, with PyTorch FX transformations leading the charge. These transformations typically rely on a set of human-engineered module-level rewrite rules which are not scalable to diverse model architectures. To address this limitation, we introduce Optimus, a general-purpose model transformation framework built in the PyTorch 2.x (PT2) machine learning compiler. With a concise set of predefined patterns, Optimus applies an efficient greedy search algorithm for pattern matching and replacement, while preserving model semantic. It is designed and implemented as a highly customizable and extensible framework integrated into the PT2 stack. Our evaluation shows that the framework can achieve up to 63% speedup, 6% peak memory reduction, and over 400 second compile time decrease for our industry-scale recommendation models compared to baselines. Optimus is open-sourced together with PyTorch 2.x as a customizable model transformation layer.

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Menglu Yu, Jiaqi Xu, Yuzhen Huang, Yanbo Liang, Jia Liu, Shuai Yang, Jason Ansel, Elias Ellison, Edward Yang, Brian Hirsh, Jia Chen Ren, Will Feng, Oguz Ulgen, Xu Zhao, Daohang Shi, Huaqing Xiong, Quanyu Zhu, Mingming Ding, Junqing Zhou, Ruilin Chen, Yuhang Yang, Chi-Keung Luk. 2026-07-03. Optimus: A Generic Operator-Level PyTorch Model Transformation Framework. https://arxiv.org/abs/2607.02945

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