multiple interview rounds?

[Guest]

I had an initial interview with my #1 SF in early February. They mentioned some kind of deadline the Friday after my interview, but did not specify what it was for (although I'm speculating it is a review about me?). I have heard people mention second-round interviews (with the same SF rather than being reached out to by another), but I have not heard back from my SF or SMART. Does anyone know if there is a multi-step interview process?