On scrum projects I've been on, its essentially the waterfall model. Business comes up with a product and date, product and engineer give high level estimates. Program manager creates a project with all the stakeholders, product managers then write requirements, engineers then write designs. Finally this gets translated into jira epics/stories so engineers can do the implementation. The implementation runs in sprints so engineers can feel like they are doing agile. Finally when its all done, there's manual end to end testing with product and engineering.