I think it depends. Because I used to think larger companies would have better work life balance but I have experienced and seen awesome and shitty at larger companies and so at startups.
Also, unless it's a decidedly shitty work life balance company like Amazon's (or few others which might be in general good), there usually no such things as "company's work life balance" but as I said above - team's.
I wish it was not this non-straightforward but it really depends on your team and especially on your lead/manager who actually set that tone and ensure that people work in or around that tone. A shitty manager fucks up the work life balance of the entire team which in some cases might have been awesome for years and often leads to exodus of people who preferred and more often those voids get filled by people who manager prefers and of course sings the same tune manager sings.
Also, some people say "work life balance" is personal. Fuck no. Just like there are generic health and medicine guidelines for populace in general (even though there are some exceptions) there are generic work life balance (which DIRECTLY leads and relates to mental and physical health and well being) - hours, timing, leaves, breaks, clear demarcation of "after office hours", availability expectations esp. after office hours and its frequency, stress, pressure, atmosphere etc etc - and how much agency an employee has in these or deciding on these!
So in short - my experience says manager is the decider of work-life balance in a team.
I'm curious, if you're interviewing at a company, what's the best way to figure out of the lead/team has this balance? What kind of questions could you ask without sounding like you're trying to be lazy?
What works better than it should: just take a good look at the people you are talking to.
Basically, do they look like they are chronically sleep deprived zombies? Are their eyes bloodshot? Hair kinda greasy? Movements shaky? Do they stare off into space? Reaction times slowed down? Essentially, do they look like a harried medical resident?
If it's just one person, maybe they are having a bad day, getting sick, or that's just their style. If it's everyone - you know the answer.
Why does this work better than it should? Because once you start down the path of sacrificing long term health for short term gains, there's nothing stopping you (or the management doing the pushing) from escalating further. The difference between normal and zombieland is quite stark.
Note that this is not a good heuristic when talking to managers of said team. They tend to always look fit and polished and well rested. Only the rank and file tend to look this sad.
Also, unless it's a decidedly shitty work life balance company like Amazon's (or few others which might be in general good), there usually no such things as "company's work life balance" but as I said above - team's.
I wish it was not this non-straightforward but it really depends on your team and especially on your lead/manager who actually set that tone and ensure that people work in or around that tone. A shitty manager fucks up the work life balance of the entire team which in some cases might have been awesome for years and often leads to exodus of people who preferred and more often those voids get filled by people who manager prefers and of course sings the same tune manager sings.
Also, some people say "work life balance" is personal. Fuck no. Just like there are generic health and medicine guidelines for populace in general (even though there are some exceptions) there are generic work life balance (which DIRECTLY leads and relates to mental and physical health and well being) - hours, timing, leaves, breaks, clear demarcation of "after office hours", availability expectations esp. after office hours and its frequency, stress, pressure, atmosphere etc etc - and how much agency an employee has in these or deciding on these!
So in short - my experience says manager is the decider of work-life balance in a team.