Hugo Kornelis is a fellow Data Platform MVP and friend. He runs SQL Server Fast, and we recently put up an interesting page with this title: Debugging with debugger: investigating SQL Server's internal structures. That's a great title, and it is for a presentation that he is building and getting ready to present. I suspect it will be at a virtual conference soon, but we'll see.
Hugo digs deep into the details of how things work. If you read his blog regularly, you'll learn a lot about the ways in which SQL Server processes queries. You should learn how to better tune your own queries and produce efficient code. At least that's the goal.
However, I wonder if most of you feel that way. While I see performance tuning sessions are often being the most popular topics at events, are you interested in internals? Do you actually use information from posts and presentations to dig in deeper to the way your queries are compiled and executed?
I know Plan Explorer is a very popular tool among MVPs, and lots of people download it, but I still see so many basic questions on execution plans, I sometimes wonder if people are really using the tool to change they way they write code.
If you want to learn more about query tuning, Hugo, Grant Fritchey, Aaron Bertrand, Paul White, Erik Darling, and many others will try to teach you. Just be sure you try and use the knowledge they impart in your daily work.