"There can be a lot of crossover between senior program managers and senior product managers. In my experience, it depends on the skill sets of the individuals and the company. Both roles provide leadership and oversight to cross-functional teams. Both roles have financial and operational responsibilities. Both roles have strategic planning and tactical execution duties. Depending on the company, they may both have sales and customer service duties.
The difference between the roles usually lies in the domain of focus. Senior product managers are concerned with making sure that the teams they work with are focused on planning, creating, marketing, implementing, and supporting the right things at the right time. They develop strategies to maximize a company's resources by delivering excellent products. Their focus is on advocating for the customer or stakeholder to ensure their needs are met.
Senior program managers are focused on planning, creating, implementing, and supporting in the right way with the right people. They help to maximize a company's resources by bridging everyone together operationally. Their focus is to ensure excellence, implement standards, and enable knowledge sharing."