Some applications **may** leave the application residues in `/data` partition specifically, `/data/data/com.packagename` where package name represents the particular application package.



In these directories that's where you usually find app's databases, configs as well as preferences files, which are normally preserved during reinstalling or updating etc (which is the reason I suspect they might be preserved even during uninstalls)


In any case, you can actually scan these **residual** or "corpse" files with 3rd party applications such as sd maid to have a clear breakdown.


I tested on **Android 4.3** perhaps things have changed since then, but at in basing my answer on that