I have worked since the start of my second year, and am now in my third. In my second year I worked two shifts per week, overnighters at the weekend, which wasn't ideal due to the lack of sleep. This year i've been working two-three evening or day shifts per week, and tbh three is too much, and as I get closer to exam time I may well ask for a few weeks off so I can focus on just the exams. I am on track for a first, or at least a high 2.1, and have also managed to balance a lot of extra curricular stuff around uni and my job, plus I commute to uni which takes up a lot of time, so it is definitely possible, especially as I am someone who gets started on essays and revision early so I never fall behind on anything, but it's not without stress and at times I wish I wasn't balancing so much and had more time to just chill and enjoy life like a lot of my uni peers seem to do. However, I do enjoy my job, and I am proud of the fact that I have managed to fit so much into the past few years and am still on track to get a good degree grade. I think people underestimate how much time you actually get at uni (course dependent of course), and a lot of it will be spent procrastinating (even with how busy I am I still waste far too much time like this!) but if you're smart about balancing things and just get on with work when you get it then you can fit an awful lot in.