FWIW in my 15 years of experience working in big tech in US, I never had a job in which there was an expectation of doing more than 40 hours, working weekends etc.

Such things definitely exist, but they are far less common than is often implied here on HN and elsewhere. I think this is largely because people who don't work long hours are much less likely to wax poetic about it, just because, well, it's not at all unusual or interesting.