On a multi-artifacts maven JavaEE project (not submodules, just a lot of independent modules), it has serious difficulties. Support for Java12+ is far better than Eclipse, but working on IntelliJ and using auto-formatting tools (Checkstyle and Save-Actions) makes it suffer enormously. I've never had those problems on Eclipse. I had to assign over 4GB RAM to handle more files (by default it is set to 2GB max)

Second this. I've found IntelliJ to be much faster on large codebases.