To Founders, how do you handle everything requiring your attention?

While growing the company we need to touch all parts all the time, set new systems in place etc.. The problem is task switching. We lose a lot of mental momentum where we switch between - community management - product management - code reviews & training of new coder - interviewing new people for hire etc..

What is a solution you went with that worked well for you? I feel like constantly my head is all over the place, everything is requiring my attention and I have a hard time focusing on the task at hand.