I've never worked at Tesla directly but I've hired engineers who came from Tesla, interviewed extensively with Tesla-adjacent teams, and have been in the industry long enough to have a decent read on the culture signals. This is my honest take.
The real WLB situation:
It varies dramatically by org. Autopilot and FSD teams have a reputation for intensity that's not exaggerated. Engineers there routinely described 60-70 hour weeks during push periods, which happen multiple times a year. The energy and solar teams apparently have more normal rhythms. Manufacturing-adjacent software is somewhere in between.
The 'intensity' is not uniformly demanded by managers. A lot of it is self-imposed because the culture selects for people who are genuinely obsessed with the mission. That's a different flavor of long hours than the grind-because-you'll-get-fired kind, but the output on your calendar is similar.
Things former Tesla engineers say when they leave: 'I learned a lot, faster than anywhere else.' This one comes up almost universally. 'The scope was real.' Even mid-level engineers describe owning systems they wouldn't own until staff level at other companies. 'The pay-to-hours ratio is not good.' Almost as universal. 'If I'd left earlier I'd have more money and less damage.' A sizable minority.
Management quality: highly variable. Tesla promotes technical brilliance over people management skills. Some of the best engineers I've seen come from Tesla had never had a real 1:1 with their manager.
The mission pull is real and fades: people join for the mission and it sustains them for 1-2 years pretty reliably. By year 3 the daily friction outweighs it for most people.
If you're early career and can tolerate the pace: the resume value is genuine. If you have kids or health constraints: eyes open.