[ethbr1]

For hypothetical conflicting changes (read worst case: unupgraded nodes/services can't interop with upgraded nodes/services), what's best practice for a partial rollout?

Blue/green and temporarily ossify capacity? Regional?

[cryptonym]

- Push a version with the new logic but not yet enabled, still using legacy logic, able to implement both

- Push a version that enables new logic for 1% of traffic

- Continue rollout until 100%

[nrhrjrjrjtntbt]

Can also do canary rollout before that. Canary means rollout to endpoints only used by CF to test. Monitor metrics and automated test results.

[cryptonym]

That's ok but doesn't solve issues you notice only on actual prod traffic. While it can be a nice addition to catch issues earlier with minimal user impact, best practice on large scale systems still requires a staged/progressive prod rollout.

[nrhrjrjrjtntbt]

Yep. This is definitely an "as well as"

Unit test, Integration Test, Staging Test, Staging Rollout, Production Test, Canary, Progressive Rollout

Can all be automated can smash through all that quickly with no human intervention.