Generally, I don't advocate for code getting thrown over the fence, regardless of the dynamics associated with the particular exchange. So the ideal approach here would be for the CTO to partner with a trusted engineer with some leadership capacity (tech lead, staff, etc.) and work through the architecture design and technical specifications for the project and get it off the ground and then hand that off to the tech lead that they partnered with so that they could carry it over the line, possibly with a team. Understanding the vision behind the project and why the CTO thought it was valuable is a critical aspect here. It turns what would otherwise be a low leverage project, mostly involving architecture and coding, into a much higher leverage project that's focused on educating and empowering other leaders in the organization. It also allows the CTO to stay close to the technical foundations and code so they don't lose touch with the organization that they're leading.