One recent realization is that when working at a 'billion dollar' company, the next 'billion dollar' idea will not come from myself or another engineer. The billion dollar idea has been realized. Few companies can sustain several billion dollar ideas. Only Amazon, Google, and a few others come to mind.
What we can contribute to the company is the next multi-million dollar idea. The tool that automates process x. The test framework that lets the company validate idea y.
These are the ideas that the forward-thinking engineer can contribute to an existing billion dollar company.