Setting up a Multisite instance on DreamHost isn't as easy as it should be if you want to also have SSL certificates, but it's possible with the right settings.
Tara Claeys and Liam Dempsey have a really interesting podcast where they talk to people in the WordPress community about what it means to be successful.
I upgraded from MySQL 5.7 to 8.0, but found that the service wouldn't start. I was able to fix it by manually re-running the upgrade process.
I've been learning Ruby during my sabbatical, and found the exercises from Exercism.io a great way to do that. Manually running the unit tests was tedious, though, so I setup Guard to do it automatically whenever I save a file.
WordPress allows you to have multiple theme directories, but moving themes from one to another may result in a fatal error. It's possible to fix that by updating a few options and clearing a transient.
"Even though we might have some very, very strong disagreements as we develop this thing called WordPress, at the end of the day, I think we all agree that when it impacts people's lives positively like that, it's really really special."