That's tough. Your last edit gives me the most pause: if you're good enough to be "desperately needed" for this critical pre-funding period, you should be good

That's tough. Your last edit gives me the most pause: if you're good enough to be "desperately needed" for this critical pre-funding period, you should be good enough for after, too. Don't sell yourself short: simply knowing your limits is a major skill, that will let you contribute where you can, grow where you can, and defer to others where you must. Also, having been involved since the start gives knowledge and perspective that can't necessarily be hired elsewhere. Ultimately if you want to stay -- and especially if you still have the support of your biz cofounder -- you should insist on having the chance to grow with the company, learning as you go along. And the plan for the future needs to be well understood among the principals, before the fundraising, because that process will tend to firm up roles, equity, vesting, employment agreements, etc. It's true that sometimes a member of the founding team isn't right – the commitment or skills or shared-vision isn't there, and perhaps the original title/status/equity even gets in the way of acquiring what's needed. But it sounds like you're humble and flexible enough that you should be able to retain a key role. If you are considering leaving from, or think you might be pushed out of, a valuable position, you will likely want to consult with a lawyer, separate from the company lawyer, about how to best protect your rights. (The fundraising process itself, and getting the whole company/team into "standard" documents, could either work to your advantage, or make it very easy for you to be booted with very little, so educate yourself early, to avoid signing away anything valuable.) If intimidated by the idea of talking to a lawyer, remember that many will give a free 30-60 minute initial consultation, so simply by the act of shopping around, always improving your 'executive summary' of your situation before each discussion, you'll learn a ton at no cost. (No two lawyers will have the exact same analysis, so the 5th or 10th you talk to may still improve your understanding.) And if you find someone you like, they may give you quite a bit of continuing good advice simply in return for the future-chance/option-value of representing you in a future dispute.