You are configuring service accounts for an application that spans multiple projects. Virtual machines (VMs) running in the web-applications project need access to BigQuery datasets in the…

Granting "project owner" at either project level is too broad and violates the principle of least privilege, as it provides excessive permissions beyond just BigQuery data viewing.

Granting the "project owner" role to the `crm-databases` project would give the service account full administrative control over the entire project, which is excessive for merely viewing BigQuery datasets.

Granting "project owner" to `crm-databases` is too permissive, and `roles/bigquery.dataViewer` should be granted to the service account (principal), not the `web-applications` project itself as a resource, when defining access on `crm-databases`.

The recommended practice for cross-project access is to grant specific, minimal roles to the service account of the requesting project on the resource project. Granting `roles/bigquery.dataViewer` to the service account (implicitly part of the "appropriate roles" for web-applications) on the `crm-databases` project's BigQuery datasets adheres to the principle of least privilege, allowing data viewing without excessive permissions.