Hey there. When "grit" is shown as a core value that translates to me as "we expect you to work crazy overtime constantly until you burn out." Happy to be wrong about that if that's not the case.
It is true that grit can be taken the way you said. And it's also true that Algolia being a great company to work for we get excited about work and sometime want to deliver outside 9 to 5.
Still we do ensure via regular one on one how people behave/work and we adjust/advise them when we see that they frequently work too much/burn out.
Finding the sweet spot of work life balance is hard. We want people to feel passionate about what they do instead of looking at the clock waiting to finish work.