I'd look at who the investors are and what stage they are in.

I'd look at whether or not the equity compensation plan is preferred stock or not, and what the dilution clauses look like. I'd want the investors to 'pay to play', myself included.

I turned down an opportunity like this twice. First company I turned down has stumbled along and managed to eek an existence but has otherwise generally not moved forward. They will try to exit, like below investment value, next year. I liked the product but always saw it as a great "$100,000 a year part time" business, not a $100M business. My co-founder wanted $100M business. I left. He'd probably be doing great if he followed my advice. I dodged a bullet there.

The other company I believed in a lot, had a proven executive team, but I couldn't afford the "come work for free in SFO" life. KPCB dropped $200M into it a year later. I missed the boat on that one, big time.

To answer the partners are an inventor and a c level VC fund raiser. The inventor is pouring his life in to it.

I mean how bad would it be if I was onboard for 1 year and pulled in double what I am currently making? Maybe I would save half my income a year before the company makes it?

Unless I had no other choice, I probably wouldn't take any level position at a start-up where I had doubts about viability. BTDT in the 90's.

I had a relative who did this very thing. The company ultimately didn't succeed, and he was able to return to his former job without a problem. The fact that he and his family had plenty of savings to fall back on 'just in case' was a major factor in his decision to try something new and different.

As someone else who with a similar 90s startup experience, I'd say to think about how this position would help you grow professionally as well as develop your network. This could be a stepping stone to a better position/company down the line.

How compatible are you with the other leaders from the company? Have you worked together before? How innovative is this team? If this initial product doesn't work out, are they likely to reinvent the company somehow?

The product is important, but it's not everything IMO. Are you just having doubts about it or do you think it's a complete flop?

If you don't believe in the product or the ability of the start-up to succeed, I would pass. This isn't the '90s, where a lot of fly-by-night startups did fine. The standard is much higher now. Trust your gut. Signed, someone who left a well-known company to be a c-level at a start-up in the '90s .

I am wondering if it is a good idea for the experience even though I am not 100% sold on the product.

This would be the first time for me at the C level.