Bartosz started as a quantum physicist, joined Microsoft to build the search engine for Windows and became an avid proponent of OOP. Then he got into concurrency and parallelism and now he’s evangelizing FP. He is an author of a book Category Theory for Programmers.
If you didn't know about functional programming, you could have discovered it yourself... playing the game called Factorio. I was fascinated by this world-building game and discovered that it inadvertently illustrated a lot of functional programming ideas. I was immediately able to identify functions, function objects, and functors. Then I started speculating about what features I would add to the game to implement applicatives, monads, algebras, etc. I want to share the fun of discovery with you.