I work daily on a java 8 project with about 3k files, about 5k classes. Small in comparison. When I have to rebuild indexes it takes about 10 minutes on a intel 12th gen w/ 32GB RAM, I configured Idea jvm to use 8GB RAM. It happens quite often when I have to add a dependency, somehow Idea project file get out of sync and doesn't update anymore. When opening the project it takes about 1 minutes before being usable. Every time. I basically keep the project opened just in case. I use Idea every day for about 60 different projects on java, kotlin, python, typescript, groovy... Idea is great, its features are much better than Eclipse or vscode, but with the latter I wouldn't have to wait so long when opening projects. Jetbrains want to change UI? Fine, but as a paying customer I would like other things fixed, people working on UI is not working on other fixes to do.