The CTO (Chief Technology Officer) is the executive responsible for a company's technology: technical choices, architecture, organizing and hiring the tech team, security and the ability to deliver the product. They sit on the executive committee.
The role changes enormously with the company's stage. In a startup of a few people, the CTO is often a co-founder and codes a good part of the product. As the team grows, the focus shifts to hiring, structuring the team and product trade-offs. In a large company, the CTO carries the technology vision and the relationship with the business, while team management goes to a VP of Engineering.
In industry or deeptech, the CTO also owns the scientific roadmap and intellectual property (patents, R&D). In a corporate group, the role should not be confused with the CIO, who focuses on the internal information system.
Why it matters when hiring
The right CTO depends on your stage: a large-company CTO can get lost in a startup where coding is still needed, and vice versa. Check on the resume the team size already managed and the milestones experienced (first product, fundraising, structuring a growing team). The strong signal: they can explain a technical decision in terms of cost, time and business risk.