The Developer role allows the user to create and revoke development certificates, submit certificate signing requests, download provisioning profiles, and more.
Users with this role in App Store Connect can upload binaries and manage internal TestFlight users. Their access can be limited to certain apps. These users can also be given access to reports, which allows them to download reports associated with their role. If this permission is added, the user gains access to all apps.
For full details on what the Developer role includes, go to Program Roles.
Note: All members of an organization’s team have access to membership resources and benefits. If you’re enrolled as an individual and add users in App Store Connect, users receive access only to App Store Connect and are not considered part of your team in the Apple Developer Program.