My biased view:
- Teaching assistants and section leads play a huge role in the quality of student experience. I think sometimes a supply/demand for filling these positions can result in not the best people filling them, which then can undermine the experience if your teaching assistant isn't the best.
- The system relies on teaching assistants for reviewing student code, and determining if students pass their tests. I worry what it means for ensuring students aren't progressing through the curriculum without having truly learned prior material. This goes back to having properly motivated and talented TAs too. Maybe some sort of randomized spot-checking, QA from full-time staff on this could help.
- I think sometimes the startup nature, remote-aspect, and fast iteration can mean various transitions through the curriculum aren't explained properly, but rather communicated piecemeal and students assemble an understanding of what's happening by discussing among themselves. There's a lot going on and structures are evolving constantly and sometimes instructors themselves can have trouble keeping track. I think being live in a room forces teachers to properly add ceremony and bookending structures to classes, but that can get dropped in the remote sphere.
Another thing, which is more a worry than a critique, is keeping the character/values and quality level there as it scales.