Yes, there's several diagrams in the new HAF documentation to show data flow and algorithms.
I would guestimate we have at least six devs who have a lot of experience with hived (and other sibling chains such as BitShares, Peerplays, EOS, and BEOS), and we have several other devs who are gaining familiarity with the code base.
Probably a similar number who've worked on hivemind, which isn't technically core code, but is responsible for a lot of the social media behavior of the blockchain.
that's good to hear, I hope @inertia will be able to resume the updates of the developer portal to make it a must have.
I had fun yesterday going to see what became
STEEMITafter almost 2 years stuck in their immobilism, it allowed me to take the necessary distance to realize how much HIVE has grown well and that we have acquired a robust, efficient and motivated core developer. So, knowing that you have so many HIVE skilled devs on your team plus the involvement of so many other great devs bringing their contribution is all the more reassuring from an internal as well as external perspective about our future.