As the subject says - when Studio is automated externally via API (e.g. using PowerShell) it leaves a number of "tmpXXXX.tmp" files in %TMP% temporary directory.
When the automated tasks finish successfully, the temp files are 0-byte, but when some task fails, the temp files are not truncated => it can be a huge disk space hog :(.

This is best seen by running some automatic tasks on hundreds/thousands of files...

E.g. I tried automated process which processes 1299 source files in 3 target languages - running initial "Scan", "Convert To Translatable Format" and "Copy To Target Languages" don't produce any leftover temp files; but additional assigning of previous bilinguals (which assigns 1264 bilinguals) and running PerfectMatch produces 1264 x 3 = 3792 zero-byte tmp files...