A Meta engineering team is migrating a legacy monolithic application from an on-prem environment to cloud infrastructure. The application handles internal service-to-service traffic, stores sensitive user-related metadata, and currently relies on flat network trust, long-lived credentials, and manually managed hosts.
You are the security engineer assigned to the migration review. Your task is to identify your top three security priorities during the migration and explain how you would implement them.
Present your answer as a ranked top-three list with short justification for each item. Focus on practical migration sequencing: what must be done before cutover, what can be phased in, and what would block launch if missing.
Use realistic examples, such as replacing shared database passwords with short-lived service identities, restricting east-west traffic, or enforcing deployment checks before workloads are promoted.