> For exactly the reasons mentioned in the post, they encourage people to move to other teams to build up the inter connectedness of teams while keeping employees motivated and engaged.
That isn't to avoid churn, that is to have more people around in general. If you leave your old team it means you no longer use your knowledge, the important part is to have engineers around, not to have the same engineers working on the same tasks.
For example, Google encourages churn by making it really easy to move to other teams in other areas. You don't talk to your old team again, so that is effectively the same thing as you leaving the company and them getting a new engineer, ie for the teams it is equivalent to churn.
> If you leave your old team it means you no longer use your knowledge,
If you move from Team A to Team B, you may not use your knowledge of the details of their codebase.
But you know precisely how to sort out the problems caused by the company's weird internal certificate authority, and their weird internal deployment tools, their weird internal inter-service auth system, and their weird internal multi-cloud system. That 'secure' way of managing secrets in production that makes 'unauthorized' errors almost impossible to debug? You know how to debug it. You know how to operate the purchasing system so your orders go through right the first time. You know precisely what the criteria are to get your subordinates promoted, and how to coach them to meet the criteria.
That can be worth a lot, when it comes to getting things done.
Military veterans of some theater of war are desired exactly because they will perform well in the next theater of war.
I don't think i can fully appreciate how mind-bogglingly huge a company like Google is, so it might well be the case that tacit knowledge, skills and relations acquired in one team don't transfer meaningfully to another. I would have to see it to be convinced however, even more so to make me believe this kind of transfer was the norm.
That isn't to avoid churn, that is to have more people around in general. If you leave your old team it means you no longer use your knowledge, the important part is to have engineers around, not to have the same engineers working on the same tasks.
For example, Google encourages churn by making it really easy to move to other teams in other areas. You don't talk to your old team again, so that is effectively the same thing as you leaving the company and them getting a new engineer, ie for the teams it is equivalent to churn.