Tom Preston Werner, Founder of Github
Tom, in the beginning (no need to watch the whole thing), talks about just-in-time hiring. Hiring/Partnering with someone who is an expert in Rails, payment systems, Git, etc. I think this is an important idea. In order to gather the essentials, elements should be added upon absolute need, not out of a feeling or a guess.
Another video I like from Tom. His discussion of luck is on-point. The factor of luck isn't completely out of your control. You should actively optimize your chances of getting lucky by consciously deciding when and where to be.