Youtube: I post oscilloscope views of chiptunes from other people or myself and sometimes other stuff.
Reddit: I'm only there to post stuff in the bytebeat subreddit. I don't plan to do anything else on reddit in order to preserve my sanity.
CSDB: My C64 stuff, only music for the moment.
Discord: I won't accept a friend request if I don't know you from somewhere else. I neither have a server or am looking to join servers.