Ask HN: How to get into OS/systems programming in 2023?

I graduated from college about decade+ ago, took few OS & systems programming courses, but didn't find them interesting back then. However, now, more than a decade later, I'm finding myself bored at my cookie cutter C#/Asp.net/SQL(+ cloud) job. What would be your suggestions getting into OS/System programming in 2023 ? For starters, I'm thinking about learning assembly, which I never learned.