I remember John Carlos Baez having some interesting stuff: https://johncarlosbaez.wordpress.com/ https://johncarlosbaez.wordpress.com/ Some other ones I had bo

I remember John Carlos Baez having some interesting stuff: https://johncarlosbaez.wordpress.com/ https://johncarlosbaez.wordpress.com/ Some other ones I had bookmarked the other day but haven't seen much in depth, mostly computer science based but more towards theory/math side: https://blog.computationalcomplexity.org/ https://blog.computationalcomplexity.org/ https://semantic-domain.blogspot.com/ https://semantic-domain.blogspot.com/ https://greydanus.github.io/ https://greydanus.github.io/ Also go to Terry Tao's blog and look at the sidebar, there are a lot of links to external blogs there.