This is the sort of thing that you don't recognize until you become a manager, and then you do and you watch everyone on your team run around like a bunch of kids chasing whatever caught their attention that day and it all becomes a lot clearer.

"Why are we doing this" and "how does it align with the business's goals" and more pointedly "what are we not doing so we can do this instead" and "is that the right trade-off" are all questions even very technically gifted engineers seem to have a really hard time answering.

The issue is most managers don't tend to think this specific way. They think of how to align the business goals to suit their specific needs (i.e. getting promoted).

Every single re-org I've been involved in was bureaucratic mess to give a manager a higher salary. There was no explicit reason why we needed to re-org, and no org change ever made a difference in terms of productivity. Our individual teams still operated the same.

It's not that they are useless, it's that there are often too many of them. At a previous SV org I worked for, they had roughly 1 "dev manager" for every 4 engineers. You could have 1 for every 10 and achieve the same result.

I’m not sure if that’s true. 1 dev manager for 10 engineers might be tough. The sheer number of 1:1s would be insane, much less keeping track of the career trajectory of 10 different people at 10 different parts of their lives. I guess this would be less difficult if everyone was already at senior or staff level, but you’d still have so much of that managers time sucked into 1:1s, reviews, and team retrospectives. I’m not even a manager and I start to feel neglected as an engineer once my manager juggles more than 6 other people, because I see they start to forget what I’m working on, and those 6 start to compete for attention to get promotions…

I guess you have never been a manager.

There is no way you can manage 10 engineers and still have good technical knowledge of what they do and provide directions.

I have, though the team size was 7 (company ran out of cash.) 10 may be too many. But 4 is way too small.

Also, I want to add that the team with the manager of 4 engineers, he provided no technical direction. That was my job as the "tech lead."

I think it can go either way (and at Meta, I have no idea), but team size tells you nothing. You can have a team of 4 highly productive engineers working on a specific project with limited scope and 1 manager can manage that very effectively. But you can't have that manager manage two teams, you're literally just splitting their focus (and with 4 people the manager can be hands-on). On the other hand you have plenty of teams that were at one point 4 productive people, grew to a team of 10, now the manage is very productive! Managing a team of 10 people, but in reality that team of 10 is now struggling to work efficiently and are probably producing the same value as the previous team of 4. The management structure is entirely determined by the underlying scope of the work that needs to be done - and yes, very often it goes astray, but in every direction.

You are right about team size, but in many companies, the "dev manager" is certainly not hands on, even with small teams. The last team I was on, the "dev manager" never even set up his development environment. He always claimed he wanted to get more involved, but probably had too many other priorities. If you are managing a team of 4, not making any technical decisions, not writing any code either, in my opinion, it is a bad sign. You are too out of touch. Hands on is necessary with small teams.

In those environments, all the technical work and decisions are delegated to a tech lead / staff / principal eng. The "dev manager" is there for people management and high level sprint planning. Planning can be done with very little technical knowledge since the team itself does the sizing and scoping.

Obviously not every company is the same, but that was my experience at a mid-size SV tech company.

> What do managers even do

I understood the role of managers after I joined a chaotic startup which hired a bunch of people but didn't think of management. It was a complete mess. Senior engineers didn't want to manage, or didn't know how to do it. And good managers are very hard to find.