Lichess has been absolutely fantastic platform. AS a chess enthusiast as an engineer of a chess website me and some others are building (shameless plug, https://chess67.com), they are the only platform I have worked with where so much is so easily accessible in terms of their APIs.

Their Oauth requires to special app registration nor any oauth secrets - only platform I have seen that does that.

I do wonder how this opens up ability for people to integrate Lichess’ player pool to their own apps.