> Focus on your product, outsource the rest.
What do you mean by outsource the rest?
Do you mean, "hey we're using AWS <Everything>-as-Service because we don't want to manage a DB cluster or deal with a load balancer?
Or do you mean, rely on existing available tools and stop reinventing the wheel every week?
iamleppert means: Identify your company's core competency and do that in house, but outsource or avoid that which is not your core.
For example, we're making a game. Gameplay, art, and tech is all done in-house and not with remote contractors because it needs to be -- it's the part of the product we love and the part our players will end up loving. Email, forums, chat, HR, applicant tracking systems, and git hosting are outside of our core and best handled by others.
Installing an exchange server is arguably letting email be "handled by others" because you are not responsible for how it works, just the setup and monitoring, which could be handled by in-house staff or by a contractor.
My point is that "focus on the core competency" doesn't have to mean "make our company reliant on a dozen other SaaS businesses who may go offline or change their business model/functionality on a whim"