Yan Chen is a second-year Ph.D. student at Industrial Engineering and Operations Research Department, Columbia University, where he is working with Prof. Ward Whitt and Prof. Jing Dong. Before that, he earned a bachelor degree in Mathematics from Tongji University and a master degree in Operations Research from Columbia University. His primary research focuses on the intersection of queueing theory, optimization and applied probability, explores the extreme performance of complex queueing systems. Additionally, He is interested in designing and analyzing stochastic models for service operations. He is currently working on exploring extremal single server queues and multi-server queues given moment conditions.