spent four years at Deloitte before moving to a corp strategy role. people ask me about WLB there all the time so I'll write it down properly.
short answer: it depends more on your practice and your specific engagement than on Deloitte as a whole. I mean that genuinely.
the better side: the people are generally sharp and well-meaning. the training investment is real, especially in years 1-2. Deloitte University in Westlake exists and they actually use it. if you join a team with a good managing director who buffers client pressure, you can have a mostly sustainable schedule.
the harder side: travel. if you're in consulting (not advisory, not audit, not tax, but consulting proper), expect 3-4 nights a week on client site in years 1-3. that's not a rumor, that's just the model. some engagements let you work regionally. others don't. you find out when you get staffed.
hours: 55-60 in a busy engagement week is normal. 70+ happens during transformation project sprints. it's not constant but it's not rare either.
culture varies by practice: federal/government services tend to have slightly lower velocity than commercial. risk advisory is more predictable. M&A/strategy work is intense but usually shorter engagements so you come up for air.
one honest thing nobody says out loud: the culture at the team level is shaped almost entirely by who your manager is. I had two managers in four years. one was a grinder who expected availability until 10pm. the other actively blocked client overreach. same firm, completely different experience.
if WLB matters to you, interview the team and the manager, not the firm. ask specifically: what does a typical week look like when we're in delivery mode? what does a good week look like? those two questions tell you more than any Glassdoor rating.