If you hire a dedicated team or use project-based outsourcing, you can stay in touch with the project manager to monitor the progress. In some cases, you may be in direct contact with one of the developers or a team lead.
Besides, most outsourcing software development teams rely on project management solutions, like Atlassian, Asana, or Trello. There, you can monitor the tasks, roles, status changes, and any other updates to keep track of the progress. As most teams rely on Agile development, regular meetings and calls are built into the development process. You can join them to learn about the completed tasks, obstacles, delays, etc.