There used to be a couple pain points when working with Phoenix on Windows. The bcrypt library wouldn't build, something needed to be run in Administrator mode to establish their symlink workaround, and PostgreSQL is a little more irritable on Windows. SASS (some node dependency in the Javascript asset managing stuff) also flat out didn't work on windows, but there was a drop-in replacement.

I know the SASS issue was solved (as a side effect of eliminating the node dependency), and I believe the bcrypt issue was, too.