There are several tickets in the PHPC-837 epic about adding an axis for various things to the Evergreen matrix (e.g. SSL, MongoDB version). The final matrix need not test every possible combination.

This ticket can be used to outline combinations that we actually care about testing. For example, it may be sufficient to only test different MongoDB storage engines on a single operating system, since we wouldn't expect the driver to perform differently. On the flip side, we probably want to test various MongoDB topologies on each operating system.

Note: variants and tasks are defined/explained in How to Read Evergreen.