Note based social network similar to facebook is a very cool idea.
Network will have features similar to facebook.
Friends can post and get other friends notes feeds based on different parameters, one parameter is topic like Concurrent Data Structures, Kafka, Interview problems and more.
Comments and other interaction buttons will also be available.
There will be access control as well as general feeds of notes which are available to public.
This network should gain attention as demand of notes is almost very high always and boosts work  productivity too.