An executive sponsor (or sometimes, product/project sponsor) is someone on the management or executive team who is responsible to the business for the success of the project.
Typically, in SaaS, there are two types of executive sponsors—one from your side and one from the prospective customer’s side.
An executive sponsor from the customer side may be your contact’s manager, the CFO, the CMO, or even the CEO. When choosing a sponsor, make sure you pick someone with the right level of credibility and decision-making/influencing power in the customer company. The ideal executive sponsor will be someone with the right balance of seniority (to align the project to the larger organizational goals), subject matter expertise (to support problem-solving and prioritization), and commitment.