CTO can be an important leadership hire for a company. As it continues to grow CTO adds value to help scale the technology & platform, dev organization and leadership presence with investors/market.

Your networks are always a great source to find such talent - LinkedIn, Founder dating, Angel List and clarity are few forums I would recommend connecting with prospective tech leaders. In addition, depending on your geographical region there are always great startup and tech events to connect with your future CTO.