It does not even have to be successful. After getting repeated feedback about my strengths as an entrepreneur and how it is not a good fit for that position, I am now toning that down a lot. YC advertises that funding a company is always good career choice because even if you fail it will be good in your CV. But my experience so far is that many companies see it as a red flag.
This is kinda fair, though. People who have run their own business make for really, really, awkward employees. It takes a really skilled manager to deal with them properly
