There are a lot of issues that will come up through out the process that require "general" technical know-how. My cofounder and I are both technical, so we lear

There are a lot of issues that will come up through out the process that require "general" technical know-how. My cofounder and I are both technical, so we learn the biz side of things as we go and the tech just happens easily. But your tech cofounder should have a good understanding of back and front end coding. Pick a language and run with it. Also, it's not just about building the web app but also deploying. So being comfortable behind a unix terminal and utils goes a long way toward making your life easier.