Comment by mattsfrey

Keep code as simple as possible, shun abstractions until the refactor stage, adopt a language / toolchain that enforces a modular / functional discipline. EDIT: also, reading the comments here - absolutely shun DRY, be very explicit with code and don't try to couple anything until its absolutely clear that is the way to go. This in my opinion is the true mark of somebody experienced with codebases that grow unmanageable vs the less initiated -- the latter are always trying to reduce code by coupling things into abstractions, the former wait until it absolutely makes sense.