From the interview (it's way down the page): > The most challenging thing is the absence of the specification. I had to infer everything just from test cases.

From the interview (it's way down the page): > The most challenging thing is the absence of the specification. I had to infer everything just from test cases. > The second thing is the velocity of tsc. It's way too fast, and I was unsure if I could follow it up. So I decided to use semi-automated translation and selected Golang. > But it was too boring, and more importantly, my programming ability has improved enough to follow tsc only by myself.