How can I learn to scale my project?

This is a question asked on the ycombinator list and there are some good responses. I gave a quick response, but I particularly like neilk's knock out of the park insightful answer:
  • Read Cal Henderson's book. (I'd add in Theo's book and Release It! too)
  • The center of your design should be the data store, not a process. You transition the data store from state to state, securely and reliably, in small increments.
  • Avoid globals and session state. The more "pure" your function is, the easier it will be to cache or partition.
  • Don't make your data store too smart. Calculations and renderings should happen in a separate, asynchronous process.
  • The data store should be able to handle lots of concurrent connections. Minimize locking. (Read about optimistic locking).
  • Protect your algorithm from the implementation of the data store, with a helper class or module or whatever. But don't (DO NOT) try to build a framework for any conceivable query. Just the ones your algorithm needs.

    Viewing an application as a series of state transitions instead of a blizzard of actions and events is a way under appreciated design perspective. This is one of they key design approaches for making robust embedded systems. A great paper talking about this sort of stuff is Mission Planning and Execution Within the Mission Data System - an effort to make engineering flight software more straightforward and less prone to error through the explicit modeling of spacecraft state. Another interesting paper is CLEaR: Closed Loop Execution and Recovery High-Level Onboard Autonomy for Rover Operations.

    In general I call these Fact Based Architectures. I'm really glad neilk brought it up.