IMHO, code sharing between the frontend and backend is very hard to do properly and you have more changes of making stuff too generic and unmaintanable faster.

IMHO, code sharing between the frontend and backend is very hard to do properly and you have more changes of making stuff too generic and unmaintanable faster. KISS As any new project, go with you're most comfortable with, so you can prototype and changes things faster. After you reach a good size and understanding of the problem you may refactor stuff for a different language/framework with better reasons for it. That being said, if you want to use Python but not a "batteries included" framework like Django, so you have better control of the stack, check out Pyramid, it is really good and scales (I'm talking on code maintainability, but also performance-wise) very well from pet-project phase to complex applications.