SSH into instance and run netcat against the port, nc -zv [localhost](http://localhost)6565
Hit the admin port and its health check
If all else fails, add a bunch of logging
IntelliJ
sbt clean
Build > Rebuild Project (required sometimes because running sbt on the command line steps on IntelliJ cache)
File > Invalidate Caches > Restart
Close IntelliJ, delete .idea folder, and re-import project
Nuclear option: make sure all changes are committed, close IntelliJ, run git clean -xdf (deletes everything not in the git index), and re-import project