Rajeev Thakur is an Argonne Distinguished Fellow and Deputy Director of the Data Science and Learning Division at Argonne National Laboratory. He received a Ph.D. in Computer Engineering from Syracuse University. His research interests are in high-performance computing, parallel programming models, runtime systems, communication libraries, scalable parallel I/O, and AI and machine learning. He has been involved in the definition of many versions of the Message Passing Interface (MPI) standard and is a co-author of the MPICH implementation of MPI and the ROMIO implementation of MPI-IO, which have thousands of users all over the world and form the basis of many commercial MPI implementations. MPICH received the 2024 ACM Software System Award. He was Technical Program Chair of the SC12 conference and was a member of the Steering Committee of the SC conference series in 2015-2018. He is a Fellow of IEEE.