It has to find and validate the model, but that's an amorphous goalpost. Startups stop being startups retroactively. They could look back a the recent past and

It has to find and validate the model, but that's an amorphous goalpost. Startups stop being startups retroactively. They could look back a the recent past and say, "that point in time was when we finally validated the business model that we're now kicking ass on, that's when we stopped being a startup and became a fast-growing company."