CVMFS has been essential in making a uniform user-facing software environment available throughout our distributed infrastructure (we have 5 different clusters located across the country, totalizing over 250k cores, close to 2k GPUs, and something like 200PB of disk storage).
It is a proven geo-distributed redundant and high performance (through local caching) filesystem which enables a install-once-available-everywhere strategy. Our software stack currently hosts over 1150 different scientific software packages in over 2800 versions, and built optimized for multiple CPU architectures, totalizing nearly 10k different builds. This is in addition to nearly 10k python packages which we make available in the form of python wheels.
Our software stack now is close to 8TB in size, and contains tens of millions of files.
Next week there is a workshop with talks from some of the users: https://indico.cern.ch/event/1079490/timetable/#20220912.det...
Even if you're not a researcher it's worth checking out for the technical accomplishments.