Juncheng Yang
Assistant Professor of Computer Science, Harvard University
Talk: Rethinking Storage for Sustainable AI: From Models to Generated DataThe rapid growth of AI is creating a new storage sustainability challenge. Modern AI systems produce and retain enormous amounts of data—from billions of model checkpoints and fine-tuned variants to an ever-growing volume of AI-generated content. Yet today’s storage systems largely treat these objects as conventional byte streams, ignoring the rich structure and semantics introduced by AI workloads.
In this talk, I will present our recent work on rethinking storage systems for AI data. I will first discuss ZipLLM, which exploits relationships among models and combines model-aware compression with deduplication to substantially reduce the footprint of large model repositories. I will then present TensorDex, which pushes this idea further by treating tensors, rather than files or models, as first-class storage objects and exploiting relationships among tensors across an entire model ecosystem. Finally, I will discuss LatentStore, which revisits a more fundamental question for AI-generated data: do we need to store the generated object at all? By storing compact model-native representations and reconstructing data on demand, LatentStore trades increasingly inexpensive computation for reductions in long-term storage.
Together, these systems illustrate a broader opportunity: rather than applying traditional storage techniques directly to rapidly growing AI data, we can redesign the storage stack around the structure, semantics, and regenerability of AI workloads. I will conclude with a broader vision for sustainable AI storage, where computation and storage are jointly optimized to reduce the growing resource and environmental footprint of AI.
Biography: Juncheng Yang is an Assistant Professor in Harvard John A. Paulson School of Engineering and Applied Sciences. His research interests broadly cover the efficiency, performance, reliability, and sustainability of large-scale data systems and machine learning systems.
Juncheng's works have received best paper awards or honorable mention at VLDB'26, VALUETOOLS'24, NSDI'24, NSDI'21, SOSP'21, and SYSTOR'16. Juncheng was a Facebook Fellow, recognized as a Rising Star in machine learning and systems, and a Google Cloud Research Innovator. His dissertation on designing efficient and scalable cache management systems received the CMU SCS Doctoral Dissertation Award and the ACM SIGOPS Dennis M. Ritchie Doctoral Dissertation Award.
His works have been widely adopted. For example, S3-FIFO and SIEVE are adopted for production at hundreds of companies with more than 60 open-source libraries and packages in 18 programming languages. Moreover, his group maintains libCacheSim, the most popular cache simulation library, and freeinference, a free LLM inference service.
Yuanrui Sang
Assistant Professor of Electrical and Computer Engineering, UMass Amherst
Talk: Flexible Data Centers Scheduling: Economic, Environmental, and Transmission Congestion ImpactsSimultaneously considering optimization of operating cost, greenhouse gas, and toxic emissions, this talk discusses a tri-objective, multi-period, power system-constrained framework to schedule flexible data center load. The framework Models data center power consumption as the sum of latency-critical and best-effort loads and considers the temporal flexibility of best-effort workload. The framework was implemented on standard power system test systems with data centers, and pareto fronts were obtained from the solutions. Trade-offs between different objectives are analyzed, and the impacts on electricity prices and system congestions were discussed.
Biography: Yuanrui Sang is an assistant professor in the Department of Electrical and Computer Engineering at the University of Massachusetts Amherst. Before joining UMass in 2024, she was an assistant professor at The University of Texas at El Paso, and she received her Ph.D. in electrical and computer engineering from The University of Utah in 2019. Her research interests include power system operation and planning, grid-enhancing technologies, and the integration of flexible load, such as data centers and electric vehicles, in power systems.