What is the principle of least privilege and why is it critical in DevOps?

The principle of least privilege (PoLP) states that any user, process, or service should only have the minimum permissions necessary to perform its function — nothing more.

In DevOps this applies to:

• IAM roles: A Lambda function that reads from S3 should only have s3:GetObject on that specific bucket, not full S3 access.
• Kubernetes RBAC: A deployment automation service account only needs update permissions on Deployments, not cluster-admin.
• CI/CD tokens: A build token should be able to push to a registry but not manage IAM users.

Blast radius reduction: if credentials are compromised, least privilege limits what an attacker can do.