[jypepin]

we as human are expected to stay 8hrs in the office because that's what our culture says: 40hrs a week is a normal work week. But if you analyse what we do in the office: barely ANYTHING.

My advice to you: As a Junior, you should expect good mentorship and support from your more senior peers and your manager. So lean on this. Make sure that the expectations between you and your manager are clear. Ask your manager the productivity he expects you to have. What tasks are expected to be done either daily, weekly or in the sprint. Try to see also what other engineers of your level are accomplishing. Once this is a little more clear to you, then forget about hours, butt in seat, etc. Do those tasks and find the sweet spot. If the expectations take you 1hrs/day, take a little more work, because performing better than expectations will make you feel good and motivate you (and probably be good for your career). If it takes over, say, 4-6hrs/day, the expectations might be a little too much, or you might need to growth a bit more and learn how to be more productive.