There are a few things you can do to verify our CTO’s skills.
First, you can ask the CTO for references. If they have previously worked with other companies, they should be able to provide you with contact information for those companies so that you can speak to their former employers.
Second, you can look at the CTO’s LinkedIn profile. This will give you a good overview of their professional experience and what technologies they are familiar with.
Third, you can review the CTO’s code on GitHub or Stack Overflow. This will give you a good sense of their coding abilities and expertise.