Preview high-impact changes

Shadow execution gives reviewers a safer place to inspect the likely impact of a supported mutable action before it reaches production. It records the preview context, estimated impact, isolation state, and eligible recovery material.

Use shadow execution when

an action changes production or customer data;
the blast radius is difficult to judge from intent alone;
a reviewer needs an impact estimate before approval; or
the workflow requires a prepared rollback path.

Keep native backups, transactions, and recovery procedures in place. Shadow execution adds another safety layer; it does not replace the destination system's controls.

Review the preview

Before approving the real action, compare:

requested operation and target;
environment and isolation state;
freshness and identity of the mirrored state;
estimated rows, resources, or cost affected;
network or external side effects;
pre-state and post-state references; and
rollback eligibility and limitations.

Treat missing isolation, stale state, or an unexplained target mismatch as a stop condition.

Prepare rollback before approval

For an eligible action, confirm that the rollback record is active and tied to the expected pre-state, post-state, and reverse operations. Identify who may execute it and how the team will verify recovery.

Some effects cannot be reversed cleanly—for example, a message already sent to a customer or a request delivered to another service. Design compensation for those effects separately.

Safe operating workflow

Verify the action is supported for preview.
Confirm isolation and mirrored-state freshness.
Run the preview and review the impact estimate.
Require human approval for material impact.
Confirm backups and the recovery owner.
Execute through the governed path.
Verify the production result in the destination system.
Use rollback only when its guards and recovery assumptions still hold.

Next step

Review the final action and surrounding evidence in Flight Recorder, and tune Policies and controls based on what the preview revealed.