Comment by BrandonM
In the past, I would have also found it strange to see tech blowing up in a tight job market. After a decade on the team-building side, though, I feel different.Interviewing and onboarding are a huge distraction. Interviewing and onboarding done well require hours of attention from the more senior folks on your team.
When a company is hiring, the senior folks involved might be spending 6 hours a week interviewing. For example, I might have 4 45-minute interviews, another 15 minutes prepping for each interview, 15 minutes writing up feedback for every interview, 30 minutes in hire/no-hire discussions for candidates who are close, and another 30 minutes in hiring or interview meta-discussions.
Onboarding takes even more time. If I'm a new hire's onboarding mentor, I'm likely spending their first couple of days close by to answer any and all questions. After that, my work is frequently interrupted for a few weeks as I help them through issues (totally legitimate issues, BTW). We'll be spending extra time pairing with the new hire during the feature development process. Code review for new hires' code takes a lot longer, too.
When you factor all that in, a hiring freeze can realistically free up 10 or more hours of experienced employees' time every week. These are some of the most productive employees on the team.
In that context, it's not especially surprising to me that giving the most productive engineers 33% more productive time would lead to rapid improvements for tech companies, in the short term anyway.
Of course, in the medium-to-long term, a company that's not hiring is building up a huge "personnel debt" that is going to come due eventually. The product improvements will lead to new business, more clients will require more support, the new business will lead to more feature requests, and some employees will move on. The company will find itself without enough personnel to make headway on their product. Then they will have a hiring blitz where they wreck everyone's productive time and the team culture. The new, bigger team will make some headway, but they will still look less productive than the team was during the hiring freeze. The business will stagnate. The company will enact a hiring freeze, or perhaps even lay off team members. And then we're back at step 1.