I have a file that I'm storing on Google Drive and I update it frequently with new versions (multiple times a day, sometimes). So far, when I copy the link from the "Share" window that allows other people to see the file, that link ceases to work after I upload a new version. Is there a way to make a link that links to whatever the current version of a particular file is?
If you want to be able to use the same share link you need to upload your new file as a new revision not a new file. Every time you upload a new file it will generate a new share link. However, if you upload a revision it will keep the same share link every time.
To upload a new version of a file using the web interface:
Old revisions are kept per Google for 30 days or 100 revisions whichever comes first. Ofcourse from this same option you can delete or save revisions yourself.