Ask HN: How flaky are your builds?

For those who work on large monoliths with > 50 active developers

Maintaining master build success rate above 80% seems to be a big problem at this scale.

More processes and check help, but only to an extent, and have side effects.

I'm interested in hearing what percent of feature / master builds you run are flaky?

How does your build champions ensure that a failed build doesn't end up blocking several hundred developers?

Is it even possible to control the entropy at this scale, or futile effort?