Looking over the 7 comments so far on this, I suggest you trust your instincts that this isn't a tremendously well-conceived business. Find someone else whose Rails skills you find are roughly comparable to yours, and say you are too booked to commit to sling the code for them, but you would be happy to serve in a technical advisory / oversight capacity as a board member, and here's this other Rails coder who should be able to serve your needs almost as well. Typical board member time commitment is no more than 16 hours a month for a director who is conscientious, with no chair commitments on a board, but one who preps for the board meetings, is available for ad-hoc and committee meetings, etc. Typical compensation is entirely equity, around 2% at the pre-seed stage for each director. Read up on what board of directors do in a startup if you take this advice and use it, before you approach them; don't go overboard, an evening spent Googling around is sufficient at your stage with these guys, you just need to get a feel for the boundary between guidance / advice and operations.

This delivers several objectives:

* Puts out the message: your professional time is outbidding their bid in the market. * Retain the relationship for a more manageable time commitment. * Allows them to get strategic-level technical advice from you "for free" (for now), and implement in the trenches as they see fit. * Gives them a starting point for another in the trenches implementer.

Expertise matters a lot. Execution matters more.

It can cost very little to offer general board-level guidance (making sure they are asking the right questions) using your expertise if like in your situation you are favorably disposed to the parties. It should cost very dear for you to use your expertise to execute.