A CTO is required – to quickly evaluate an existing technology platform, team and processes, and, rapidly implement necessary changes, to guide corporate decision making on the role of technology and in allocating budgets, to hire a technical management team, including a VP of Engineering, to help define a technology architecture aligned with the business strategy.
Mentioning that a CTO is not needed if you have a good VP of Engineering – at least till you reach a cash flow positive state. As the company reaches a certain size and there is an increment in the range of products and there is a need to have a credible roadmap – then some combination of CTO and VP of Product Management is needed to think things in terms of internal system as well as with customers.