I built a TicTacToe game to learn the .Net MVC3 framework. The basic functionality works (display board, make a move, detect winning move etc.) What I'd like to do is make it a "real" application - well-architected and using the right technology at the right layer. For instance, I'm currently saving every move to the database via a service call, which feels klugey and may become a bottleneck if this was an MMO game.

How do you determine a good architecture (or right set of technologies) to use in a situation like this? I'd like to learn not just what to do, but why certain decisions are better than others.

I noticed a similar thread here but it just offered opinions without explaining WHY something would be better (e.g. why Node instead of MVC3, etc.)