Tetzaveh - Mishkan, Aharon, and the Sin of the Golden Calf

Parashat Tetzaveh offers us a vantage point onto the place of sin in our reality.  There is a well-known debate between Rashi and Ramban about the placement of Tetzaveh vis a vis the Sin of the Golden Calf. Was the command to build the Mishkan given before the Sin of the Golden Calf as a way to continue the experience of the Revelation at Sinai, or was it a way to facilitate an atonement process after the Sin of the Golden Calf?

We look at the implications to gain insight into the function and role of the mishkan according to each view – how does each deal with possibility of sin,  and failure? And where does Aharon fit in with all of this?