These da Vinci style drawings were likely created using the SketchUp models from sometime ago, which you can download from the page below to play with:
At CERN, software stacks are created centrally and software distribution for experiments is done with CVMFS (https://cernvm.cern.ch/fs/), an HTTP-based read-only FUSE filesystem.
EESSI (https://eessi.io) has taken this model further by using CVMFS, Gentoo Prefix (https://prefix.gentoo.org), and EasyBuild to create full HPC environments for various architectures.
CVMFS also has a docker driver to allow only used parts of a container image to be fetched on demand, which is very good for cases in which only a small part of a fat image is used in a job. EESSI has some documentation about it here:
https://www.eessi.io/docs/tutorial/containers/
CERN is a heavy user of ceph, with about 100PB of data across cephfs, object stores (used as backend for S3), and block storage (mostly for storage for VMs). CVMFS (https://cernvm.cern.ch/fs/) is used to distribute the software stacks used by LHC experiments across the WLCG (Worldwide LHC Computing Grid), and is back by S3 with ceph for its storage needs. Physics data, however, is stored on EOS (https://eos.web.cern.ch) and CERN just recently crossed the 1EB mark of raw disk storage managed by EOS. EOS is also used as the storage solution for CERNBox (https://cernbox.web.cern.ch/), which holds user data. Data analyses use ROOT and read the data remotely from EOS using XRootD (https://github.com/xrootd/xrootd), as EOS is itself based on XRootD. XRootD is very efficient to read data across the network compared to other solutions. It is also used by other experiments beyond high energy physics, for example by LSST in its clustered database called Qserv (https://qserv.lsst.io).
I think this is good advice overall. I wrote a CMake script that does most of the heavy lifting for XRootD (see https://news.ycombinator.com/item?id=39657703). The CI is then a couple of lines, one to install the dependencies using the packaging tools, and another one calling that script. So don't underestimate the convenience that packaging can give you when installing dependencies.
I was just taking a look and couldn't help but notice the switch statement for your operator[], which likely causes a lot of unnecessary bad speculation at runtime:
Many believe the C++ compiler will magically optimize the switch away, but in some cases, like the example above for CLHEP, it doesn't happen, so you end up with bad performance.
https://twiki.cern.ch/twiki/bin/view/CMSPublic/SketchUpCMS
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