Boot drive fills up for no reason

Is it normal???

I have a DIY NAS with an old dell optiplex, the boot drive with the OS only is on an nvme 128GB ssd and a separate raid 1 array with 2x 6TB hhds for mass storage.

The install is fresh, I might have installed and uninstalled a couple of apps but I still have to use seriously this nas and the boot drive is almost full ffs!

This might be the 3rd or 4th installation I have formatted and reinstalled just for testing purposes. Since with the 1st tests and having the os and apps installed on the ssd the latter gets filled extremely quickly it was Gemni’s suggestion to move everything on the raid array except for the os.

I did that and lo and behold everytime I install and app it creates a dedicated folder in the AppData folder on both the ssd and the raid array, is tis normal and how can I get around this? I’m not planning on buyng a bigger ssd for the moment, I’m fine having the apps running on the raid only.