The constraint that shaped everything
An election has a fixed date. Every other deployment I had run allowed some negotiation on timing — this one did not. That single fact decided the whole design: the pipeline had to be judged on its worst day, not its average one, and it had to make partial failure visible early enough to still be fixable.
The volume was 6,000+ devices spanning Windows, macOS, iOS, Android, and VR hardware. Mixed estates are where device tooling usually breaks down, because each platform has its own enrolment model and its own failure modes.