For one client, I have to deliver a build they use in QA and production. The checksum of the build file has to match - it cannot change at all between QA and production. The configuration for each environment is different, so I have a build that contains just the code and then a separate build for each environment that contains just the environment specific config files. The config file builds puts the files in the same location regardless of environment, so the code can always load c:\myapp\myconfig.xml which will contain the settings for that environment. Most articles I read about this (such as For one client, I have to deliver a build they