I met Joe in 2012 when I spoke at the Erlang Conf in SF. he is the reason I discovered functional programming and the whole concept of message passing (actor model) in distributed systems. Quite a legend and contributor to the world of computer science. RIP joe.
I also met him at a conference in '16. He gave a talk but mostly wanted to shoot the breeze in the hallway with fellow hackers. He lamented scheduling gripes with his PM, being a slave to Jira, and some new things he was playing with. Very approachable and humble.
He asked a few of us hanging around what talks we were thinking of attending and we agreed to check out something about concurrency in some modernish platform. The speaker was working on issues with handling failures, message passing, memory management, etc, but then realized Joe was in the back and pointed out it had all been solved many years ago by that guy over there. Everyone laughed and gave Joe the acknowledgement.
I don't feel like we've finished learning from and building on his work. RIP.
