Disaster Recovery Strategy: RPO/RTO-Driven Decision Framework#

Every DR conversation starts with two numbers: RPO and RTO. Recovery Point Objective is how much data you can afford to lose. Recovery Time Objective is how long the business can survive without the system. These numbers drive everything – architecture, tooling, staffing, and cost.

The mistake most teams make is treating DR as a technical problem. It is a business problem with technical solutions. A payment processing system and an internal wiki do not need the same DR tier, and pretending they do either wastes money or leaves critical systems exposed.

IAM: Identity and Access Management#

IAM controls who can do what in your AWS account. Everything in AWS is an API call, and IAM decides which API calls are allowed. There are three concepts an agent must understand: users, roles, and policies.

Users are long-lived identities for humans or service accounts. Roles are temporary identities that can be assumed by users, services, or other AWS accounts. Policies are JSON documents that define permissions. Roles are always preferred over users for programmatic access because they issue short-lived credentials through STS (Security Token Service).