A good way to learn more about a company’s work-life balance is to ask!
If the answer mentions coming in early, staying late, and working weekends, that tells you a lot about the company’s culture and the kind of work-life balance you can expect.
However, you may not get that specific of an answer. If you have lingering doubts, try asking if staff are expected to answer emails or phone calls during the evening, weekend, or even while on vacation.