Boundaries make responsibility visible

One system, several lenses

A rectangle on a diagram is only the beginning

Technical components are one boundary. Data, identity, organizations, operations, and decision authority create other boundaries that may not line up with the same rectangle.

A review becomes clearer when it names the boundary being discussed instead of treating every scope question as architecture.

Inspect the seams

Connections create handoffs, not shared ownership by default

When an application calls a managed service, the connection does not make the provider responsible for application data design or permissions. It creates a handoff with duties on both sides.

Name the interface, expected behavior, failure behavior, evidence, and escalation route at each important handoff.

• What crosses the boundary?
• Who controls each side?
• What happens when it fails?
• Which evidence shows the handoff works?

Read decisions precisely

Approval has a boundary too

A platform decision can establish a reusable direction without approving every application that may use it. Provider assurance can support a decision without proving that a particular configuration is safe.

Always state the subject, scope, conditions, authority, and date of a decision.