A while back, before I started working through Rustlings myself, I came across a Rustlings YouTube tutorial (I think it was part of a series of three) where one of the language creators and a relative newbie worked through Rustlings together. What was interesting about it was that the language creator would also offer insights into design decisions along the way.
Unfortunately, I can't locate this series, even though it should be in my YouTube history. I don't think it has Rustlings in the title though, so makes it tricky to find. Any help?