By having no pure managers.

Everyone who is a manager actively makes independent contributions for a not-insignificant portion of their work-week.

So, when we have 1-on-1s with them, we can actually discuss improvement avenues from the same vantage point. Not some spreadsheet pushing manager who has no clue how to measure engineer-productivity or performance.

When they do code reviews, their comments serve as an important learning opportunity, pointing out good practices/conventions, etc.

And finally, when you disagree, it's backed by the validity of your points as 2 engineers, rather than their authority as a manager vs you, their direct report.