Julien Loiseau

Scientist and Handyman

Profile Picture

About Me

I'm a High Performance Computing (HPC) scientist in the Co-Design Team at Los Alamos National Laboratory (LANL), and a member of both the LANL AI Strike Force and the ISO C++ Standards Committee. My research focuses on exploring emerging parallel and distributed architectures to enable the next generation of supercomputers for scientific simulation.

I work across several key HPC and AI projects, including topology development in FleCSI, GPU acceleration with Kokkos in the ExaShEDS project, and multi-physics modeling as the lead computer science developer for FleCSPH, a Smoothed Particle Hydrodynamics framework.

I'm also the lead of the Co-Design Summer School at LANL, a 10-week immersive program where six students work collaboratively using a co-design approach to tackle a shared scientific computing challenge. The school emphasizes teamwork, hands-on development, and exposure to cutting-edge HPC and AI tools.

Beyond my work at LANL, I'm an active member of the broader scientific computing community. I'm involved in the SC Conference Series (Supercomputing) as part of its technical committee, and I’ve been a member of the IEEE for several years. I also serve as a reviewer for the United States Research Software Engineer Association (US-RSE), supporting the advancement of research software practices in the U.S.

Areas of expertise: HPC, AI for science, C++, accelerator programming (GPGPU), performance optimization, and large-scale multi-physics simulations.
Current projects: FleCSI, FleCSI-SP, FleCSPH, ExaShEDS, AI Strike Force.

Hobbies & Interests

Outside of HPC and research, I enjoy a range of hands-on, creative, and outdoor activities.

  • Wildlife Photography: I love capturing nature through my lens. Most of my photos end up on Instagram, when I find the time to sort through them!
  • Woodworking: I spend a lot of time in the workshop making furniture. I’m especially fascinated by Japanese joinery and am working to improve my skills in that area. I might even share some of my projects here.
  • Japan: I have a deep love for Japanese culture and am learning the language with the goal of attending woodworking classes there someday. I’m also dreaming about buying an Akiya (abandoned house), eventually!
  • Hiking: I enjoy getting outside whenever I can, especially with my dog, Louis. Nature is my recharge button.
  • Music & Art: I play the trumpet and have performed in several bands in both France and the U.S. I also enjoy painting, whether it's with oils or miniatures like Warhammer 40K.