Changing software in the field.
WHY IT IS ESSENTIAL
Vulnerabilities are found, and unpatchable devices remain exposed permanently.
WHAT THE UPDATE MUST SURVIVE
Power loss partway Connection loss partway A corrupted image An image that runs but does not work
WHAT THE STANDARD PATTERN IS
Download fully and verify before applying Write to an inactive location Switch on restart Confirm operation, or revert automatically
WHAT CONFIRMATION MEANS
The new version proving it works, including connecting successfully.
WHY THAT SPECIFIC CHECK
An update that runs but cannot connect is unrecoverable without it.
WHAT TO VERIFY BEFORE APPLYING
A cryptographic signature.
WHY
Otherwise anyone able to deliver an image controls the fleet.
WHAT BANDWIDTH CONSTRAINTS REQUIRE
Differential updates, sending only what changed Scheduling during low-cost periods Staging across the fleet
WHY STAGING MATTERS MOST
A defective update applied everywhere simultaneously can end a deployment.
WHAT TO STAGE
A small group, then progressively larger.
WHAT TO MONITOR DURING ROLLOUT
Success rate Devices failing to return Behaviour changes after update
WHAT TO PREPARE
A halt, executable immediately.
