I actually like the summer vacation hypothesis. Makes the most sense to me - backup devs handling some things they are not used to.

So, a reverse Eternal-September? It'll get better once everyone is back from August vacations?

No, because it’ll only get better until next summer.

These outages mean that software only gets more ~fool~ summer employee proof.

I'm more partial to the summer interns hypothesis.

I agree with this, but to be clear, the "summer interns hypothesis" is not "summer interns go around breaking stuff," it's "the existing population of engineers has finite resources, and when the interns and new grads show up, a lot of those resources go toward onboarding/mentoring the new people, so other stuff gets less attention."

Pretending that junior engineers is the problem, is the problem.

Just checking what your objection is. Is it that you think experience is overrated, or is it just that he was speculating without any evidence?

Can't speak for OP, but I can tell you what mine is.

If you have an intern or a Junior Engineer, they should have a more senior engineer to monitor and mentor them.

In the situation where a Junior Engineer gets blamed for a screw up:

1. The Senior Engineer failed in their responsibility. 2. The Senior Engineer failed in their responsibility.

A Junior Engineer should be expected to write bad code, but not put it into production, that's on the Senior. If I hit approve on a Junior Engineer's PR, it's my fault if their code brings the whole system down. If a Junior Engineer had the ability to push code without a review, it's my fault for allowing that. Either way it's my fault and it shouldn't be any other way. It's a failure to properly mentor. Not saying it doesn't happen, just that it's never the Junior Engineers fault when it does.

I'd caveat that slightly: only if the senior engineer is not also overburdened with other responsibilities, and the team has the capacity to take on the intern in the first place. I've been on teams where I felt like we desperately needed more FTEs, not interns. But we could hire interns, and not FTEs.

(I agree with the premise that an intern or junior eng is supposed to be mentored, and their mistakes caught. How else should they learn?)

the amount of time that the summer intern / new grad eat up of seniors time is the problem. Tech debt that does not get addressed in a timely manner because of mentorship responsibilities is the problems

If you don't train new and capable engineers, you'll eventually lose talent due to attrition and retirement. Talent can be grown in-house; engineering companies are much better environments than universities to learn how to build scalable platforms. The cost of acquisition is low, too, because junior engineers can still make valuable contributions while they learn to scale their impact.

If interns are able to take down your infrastructure, then it is the fault of the senior engineers who have designed it in a way that would allow that to happen.

Rule one of having interns and retaining your sanity is that interns get their own branch to muck around in.

Rule one of having a useful intern experience is to get them writing production code as quickly as possible. They check in their first change? Get that thing into production immediately. (If it's going to destabilize the system, why did you approve the CL? You two probably pair programmed the whole thing together.)

I completely agree- even if it's something small.

I'm an intern in a big company with an internal robotics and automation group, and I recently got to wire up a pretty basic control panel, install it, and watch workers use it. That was so cool, and made me appreciate what I was doing a lot more.

Sure. The interns have their own branch, but it doesn't stop them from being disruptive to the human in charge of mentoring them.

All changes should be in a new branch.

I used to believe this. Having solid lower environments which are identical to production, receiving live traffic where engineers can stage changes and promote up removes some of the “all things should live on a branch” business. I know that sounds crazy, but it is possible for teams of the right size to go crazy on master as long as the safety nets and exposure to reality are high enough in lower environments.

I recall someone saying that holiday periods actually had better reliability for their services, because fewer people were pushing breaking changes...

I do wonder if it's that the usual maintainers of particular bits and pieces are on vacation and so others are having to step in and they're less familiar or spread too thin.