Darwin regarded sympathy as the most important human adaptation

I believe, simply put, that hours-per-week are as useful a metric of progress as SLOC. The fact is that for any nontrivial development effort, adding work hours does not noticeably improve time to delivery and, in fact, starts to degrade progress.

There are a few reasons for this. First, the most important effort in any significant project takes place before anyone starts slinging code. Design and strategy are obvious examples, but programming problems of sufficient complexity also don't benefit from throwing hours at them. For example, one of our current problems can be formalized as an adversarial non-Bernoulli bandit with an unknown budget. I don't think the architect conducting the literature review is going to produce better or faster work if he went from 50 to 80 hours a week.

Second, even when everyone's got their shovels out, there isn't a linear relationship between hours and project velocity. At some point the marginal productivity per hour plateaus and, after that, quality issues and technical debt start piling up. A team with the ability to intellectually come up for air is a team that is going to deliver a better strategy, a better design, a better experience and ultimately a better product. I'd rather take an extra six months to get to market than have to pivot half a dozen times (I say, as they box up the startup next door -- sure, they shipped fast, but their strategy and their product failed, and they found that you can't get your Series A subscribed to when you have zero market energy).

I do think that for some people there's an idea that work-life balance (and I refuse to use scare quotes) shows insufficient commitment or hustle. But would you want a surgeon who boasts about how fast he can cut a patient open, rather than his or her postoperative results? An engineer who can whip out a bridge design in half the time with only a 10% higher catastrophic failure rate? Are we so insecure in the intellectual value of what we do that we have to brag about how hard we work instead of the value we bring?

I disagree. What we do is difficult, and it is intellectually challenging. If a project demands that the dev team work 10, 14, even 16 hour days through the project timeline (and I've been in all three of those positions), then there's something wrong with the project, the taskings, or the stakeholders.

We are professionals. We are intellectuals. We are not measured by the sum of our hours, but the result of our efforts. Take pride in yourself, because when you're a manager -- if you're not one already -- you need to take pride in your team.