runmode based configurations

hello,

i am using aem 6.5

so we have few configurations which are provided by aem like referrer filter or user mapper or html library manager etc.

my requirement is to update configuration from my code so that developer dont need system/console access to do changes in author or publish instance.

is it possible to do so?

also if anyone can help me with how to write custom configuration code which aem will refer as per runmodes it would be great.