I was thinking the same thing, it almost looks a little too good to be true -- although it does kinda make sense given the focus on GPU-based clusters. I wonder how this compares to Baidu's warp-ctc [1]. They don't really seem to be the same thing, and maybe I'm missing something since I'm just starting to get into ML, but it seems to be conspicuously absent from this writeup.
[1] https://github.com/baidu-research/warp-ctc