LLNL’s Lori Diachin named to 2025 ‘legends’ of high-performance computing list

Lawrence Livermore National Laboratory’s Principal Deputy for Computing Lori Diachin has been named one of HPCwire’s “35 Legends” for 2025, a recognition that celebrates pioneers, visionaries and champions who have left an enduring mark on high-performance computing (HPC).

Now in its second year, the 35 Legends class is selected by HPCwire’s editors and advisors to honor individuals whose influence has shaped the trajectory of supercomputing, from foundational innovations to community leadership. Diachin joins an elite group that includes researchers, inventors and executives known for helping advance the HPC ecosystem over the past several decades.

“It’s an honor to be recognized alongside so many pioneers and leaders in high-performance computing,” Diachin said. “The progress we’ve made in HPC — particularly in making exascale computing a reality — is a testament to the dedication and creativity of the entire community. I am grateful for the opportunity to work with such talented colleagues at LLNL, and across the Department of Energy (DOE) laboratories, as we continue to push the boundaries of what’s possible in HPC.”

At LLNL, Diachin helps leads a workforce of approximately 1,400 staff across HPC, mission-related computing sciences and information technology. She serves as a senior-level advisor to Computing Principal Associate Director Bruce Hendrickson and collaborates with division leaders and institute directors on strategies to develop and sustain the Laboratory’s cutting-edge computational capabilities.

Diachin is also chairing the 2025 International Conference for High Performance Computing, Networking, Storage, and Analysis (SC25), the world’s premier HPC conference, to be held Nov. 16–21 in St. Louis. A special luncheon honoring this year’s HPC Legends will be held during the event.

A true HPC trailblazer, Diachin has more than three decades of experience in applied mathematics, parallel computing and computational science. As a former director for DOE’s Exascale Computing Project (ECP), the largest computing project in DOE history, she played a pivotal role in steering the national initiative to accelerate the delivery of a capable exascale ecosystem. Her tenure helped ensure application teams and software developers had the resources and connections needed to maintain U.S. global leadership in supercomputing.

During her career, Diachin has served in numerous leadership roles in projects, program coordination and line management. For example, she served as director of LLNL’s Center for Applied Scientific Computing, a division of 150 researchers in applied math, computer science and data science, led DOE’s multi-institutional FASTMath SciDAC Institute comprising more than 40 applied mathematics research from across DOE, and managed DOE’s HPC4Manufacturing and HPC4Materials programs, which partnered national labs with industry to drive innovation using HPC tools.

Diachin is known not only for her technical excellence but also for her mentorship, advocacy for women in computing and commitment to fostering the next generation of HPC leaders. Her career path has included research roles at both Argonne and Sandia national laboratories, where she helped build early infrastructure for unstructured adaptive mesh refinement, parallel finite element methods and early uses of virtual reality environments in scientific computing applications.