Sounds about fair, assuming they agree to put you on a decent salary once they have more money. They've already validated the idea, now they need help executing

Sounds about fair, assuming they agree to put you on a decent salary once they have more money. They've already validated the idea, now they need help executing. It's not the same level of risk when you start out from square one as it is when you start out from square zero. You'd be essentially Employee #1 with a fancier title (and more sway if they take the C in your title seriously). If the amount of equity is important to you, you should go start your own startup from scratch. But if you like and trust the founders, and are excited about what you would be doing, then the equity is just a bonus for being a key player in getting the company successfully to its next stage.