I use a minimalist window manager, but I think I am in the minority, even among software engineers that use linux as their primary development environment. This almost works, except web browsers are extremely GPU heavy these days, so JavaScript laden sites (jenkins, amazon, news) often become unusable with more than ~10 tabs.

Anyway, most engineers at work use unity because it is the default, and it is a non-starter without hardware acceleration. We site-licensed vmware, and it seems to work OK.

The last time I checked, the second most common choice is fvwm. It sorta works out of the box and isn't unity. Also, it can run on the big server VM's, unlike unity (there is no 3d acceleration in the server kvm instances...)

Another common choice is to do everything via console, productivity be damned. (There are some highly productive console users, but they tend to put linux on their laptops on day one anyway)