What does least privilege mean in practice?

Question

Accepted Answer

Least privilege means every account, service and key gets the narrowest access that lets it do its job, and nothing spare. Not because you distrust anyone, but because the damage from a mistake or a stolen credential is bounded by what that credential could reach.

In practice it is mostly about resisting convenience. One admin role that can do everything is easier to build than three roles that each do less, and it means one compromised laptop is a total compromise. Splitting roles is tedious exactly once, at the start.

Apply it to machines too. A deploy key that can only deploy, a database user that can only read, an API key scoped to one service. Most real incidents are not clever: they are a credential that could do far more than the thing it was there to do.

What does least privilege mean in practice?

What are database access rules?

Where should API keys and secrets be stored?

What is the difference between authentication and authorisation?

Want this built, not just explained?