Of course it all depends on the application at hand, but databases and other system endpoints are something I treat as volatile. However, I don't commit to the

Of course it all depends on the application at hand, but databases and other system endpoints are something I treat as volatile. However, I don't commit to the madness of replicating a whole database interface in our codebase. Instead, I find it sufficient to bundle all database access in a single point. (i.e. by using a singleton class). That way, later change is much easier and it's a very low investment in maintenance.