At the moment, the contribution guidelines suggest setting up a conda environment based on the environment.yml files in the repo. I think there is quite a lot to gain from moving to pixi in the case of glum. In particular:

• There are various environment.yml files for different use cases. Pixi has an elegant way of handling multiple environments
• Certain dependencies are platform specicfic, which pixi also handles nicely (see Benchmark removal of libblas dependency #787)
• It uses lockfiles, which would help ensure that everyone (including the CI) uses the same versions of the dependencies. Especially useful for benchmarking.
• I personally find it more ergonomic than activating environments but YMMV

What would not change:

• Pixi still uses conda packages for dependencies
• The build system. Pixi can not build conda packages (yet?). CI conda builds would still be based on conda.recipe/meta.yaml and conda-mambabuild, and PyPI builds on cibuildwheel.

I can make a draft PR so we get a better idea how it would look like. What do you think?