I expect they want people who are willing to be persistent in working on hard problems that might be challenging or require learning new skills. I don’t see the implication others are drawing with grinding, long hours, overwork, etc. I don’t love the term grit as it’s been popularized but still I think the ability to deal with frustration and keep moving in the right direction on hard problems is a valuable one. A person who displays this quality can be expected to do well when faced with a job that requires learning a new programming language or working in a difficult field (including non-programming things like nonprofit work or counseling).

Grit is not synonymous with overwork. Grit is more about, when something is hard, not just looking for an easier task, but continuing to focus on the problem at hand. It doesn’t mean being a hero and figuring things out on nights and weekends. It might mean patiently reaching out to the people who can help you, following up when others drop the communication, taking responsibility for chasing requirements, etc.

Grit can also meaning sticking to your guns when it comes to boundaries and thus preventing burnout.

I guess I just would caution folks to not read too much into this word. It’s not a strong signal of anything, put it together with everything else that you see from the company. Some people just read the book Grit and want to use the term