This will depend on the project, as TS can go from very loose to very strict depending on the settings. For a project with all strict settings turned on and cas

This will depend on the project, as TS can go from very loose to very strict depending on the settings. For a project with all strict settings turned on and casts minimized, then I find refactoring is an absolute breeze. I have successfully done huge refactors that completely worked without any (known) regressions as soon as all the tsc errors are resolved. And your editor combined with the language server drives a lot of the refactoring (similar to Java/C# as you alluded to) To me this is the real killer feature of TS over JS.