Don't work for empty promises, get everything on paper

It’s just initial stage, not sure how should I go about it. I would rather ask for some founding role?

Software Engineer

Even their promises on paper is worth shit. Try to get max on monthly sal.

Consultant

Ask equity if you think it can become big.. ask money if you are unsure.. but don't do it for free.

Analyst 

Money.. not esops.. not bonuses.. cold hard cash.

I am going to start working in building a product in a startup as a Backend developer. I was approached by 2 of the founders with their design and vision. I

I am going to start working in building a product in a startup as a Backend developer. I was approached by 2 of the founders with their design and vision. I really liked it and thinking on working on the same.

But I was confused how to proceed with it? Shall I ask for money or some position? I don’t have any experience of it. Please suggest.

What do you look for when you join founders and build a product?