Get in contact with tech recruiters who are often in talks with serial tech cofounders who are looking for a new startups to join. Recruiters normally charge a fee for this, but at the early stage, you may find recruiters who will work out an arrangement with you. Placing the original tech cofounder is a sure-fire way for a recruiter to own the relationship exclusively with an early stage startup. If the recruiter believes in what you're building, perhaps they will be willing to defer payment until the company has funding or is otherwise in the position to pay fees, or work out another equity-based agreement. Ultimately, I would only select one recruiter for this type of assignment, but you can speak with several to see if they're interested. Make sure the recruiter you select is proven in exactly this type of effort... ask for a reference from another startup non-tech founder where the recruiter placed the tech cofounder.