This new implementation incorporates lessons learned from over a decade of experience working with HPC and Gadget codes,
for instance see my greentree in [Ragagnin et al. (2017)](https://ebooks.iospress.nl/publication/42679),
my GPU scheme for N-body codes as in [Ragagnin et al. (2020)](https://ebooks.iospress.nl/publication/53922)(and Ragagnin et al., 2025, in review),
my parallel tree build tests (fund by HPC Europa3, ID HPC17YMAKH), and other unpublished activities
my parallel tree build tests (fund by HPC Europa3, ID HPC17YMAKH)
in the context of OpenGadget3 (PI. Klaus Dolag).
`hotwheels` is designed to leverage CPU and GPU parallelism, with a strong emphasis on modularity. This modular approach facilitates collaboration with HPC engineers and GPU vendors, enabling efficient utilization of HPC systems. Modularity also enhances testability, simplifies the addition of new features, and allows rethinking code structure based on past experiences.
