From my experience and from many successful technical founders, or co-founders, you're either not qualified or just qualified for it. Even if you're advanced in specific areas of programming/computing, being a technical co-founder means doing everything related to the product (I'm guessing it's software). Deployment, database, web app, version control, services, server ops, etc... is a lot of stuff to learn and become proficient with it.

Don't be worried about the sheer overhead of skills or knowledge required. Startups is all about learning, maybe just as much as executing.