Nah, it's nigh-impossible to try and scale for a new code base. I can scale for, say, wordpress or drupal, because lots of people have had tons of very high traffic sites with wordpress or drupal... but if someone comes to me with their own custom app and wants scaling advice, the best you can do is generalize based on what you know. It's never going to be an exact science, and due to budgetary constraints the reality of the matter is that you usually aim low and go up from there until things work out right rather than aiming high which would require a largely initial cash outlay for hardware, bandwidth/uplinks, data center real estate, etc.
Dusk Sanatore (CNJ, FSH, GSM) @ Cactuar
Dusk D'norte (MRD) @ Kujata