If you don't know of last.fm (which is still limping along, as far as I can tell), it was (is..) a cool website where your music player of choice could tell the world what you have listened to historically & compare music tastes with some kind of Algorithm. I figured I could store that in AT Proto as well, and I guess it works.
It'll be high-maintenance though, Spotify requires 180 day renewals for apps, so the sync will eventually break at one of those expirations and I'll forget it existed. In last.fm's defense, the integration it has with spotify kept working long after I forgot about it, but I can't tell if it's very reliable.
I also accidentally deleted this blog while trying to debug the scrobbler, so I guess that's a sign to invest in staging environments for my PDS.