My two favorite talks from this year's emacs conf:
https://emacsconf.org/2021/talks/design/
On the aesthetics of text editors. I'm in violent agreement with most of his points about visual junk in modern IDEs.
https://emacsconf.org/2021/talks/structural/
A package built with tree-sitter and an elisp port of MiniKanren to provide structure editing for arbitrary languages. Nice practical use of logic programming in a context of general interest to FoC people. 🙂