Over the year's I've tried being an employee and don't mind most of what that entails. Crunch time's within reason are expected and pivoting in startup's is just the way things go. What I do have a problem with are companies that outright lie: "Oh yeah we have test coverage" from 3 years ago, "We are going to be the next Google!" but we have crippling technical debt, and other more bizarre incidents "We are fiscally sound and will last for a thousand years!" but we will start laying people off next month.
Somethings just cannot be foreseen or detected early, several years ago I was with a fairly successful startup that partially imploded because the partners could not handle the stress ( alcohol & substance abuse ). That said, besides obvious things like whiteboard interviews and out of domain technical questions (ex "How would you implement a B-tree?" for a webdev company ) is there any questions that might give a better insight to a company's soundness?