[danzheng]

One thing missing in the blogpost is in practice you see many large orgs, especially in finance, living with multiple time domains. For example, on-prem trading systems almost always use PTP or PPS for sub-microsecond timestamping, often on dedicated networks to reduce jitter (for meeting regulatory requirements like MiFID II and CAT) while the rest of their infra (in on-prem and cloud) just runs NTP for millisecond-class sync. Both protocols are fundamentally sensitive to network conditions — the mean offset may look fine, but outliers due to congestion/jitter can be very poor.

The consequence of having multiple time domains is pretty painful when you need to reconcile logs or transaction histories across systems with different sync accuracy. Millisecond NTP logs and sub-microsecond PTP logs don’t line up cleanly, so correlating events end-to-end can become guesswork rather than deterministic ordering.

If you want reliable cross-system telemetry and audit trails, you'll need a single, high-accuracy time sync approach across your whole stack.