Hello to everyone!

I just wanted to ask you all some information. I am in italian graduate in computer engineering and next friday I will be in zurich for a job interview for a phd at Eth. I wanted to ask you if you could tell me what kind of questions they may be supposed to ask me and also how much I could expect to earn from such a position.
Furthermore, I already have a proposition for a phd at Jacobs university (Bremen) with a salary of 1200 euros/month (through individual research). Then, I also wonder how much I should expect from this interview (in case I should succed) to have these two propositions competitive.

Thank you very much for your attention and cooperation!

These details are easily found on the ETH website (salary wise).

A good professor will ask you about your research interests and past abilities to see how you will fit with their present research direction and goals. They will also (if they're smart) give you time to meet the other group memembers to see how you will fit in the group.

If offered a position you will get minimum ~2900 CHF take home per month. Going up from there based on your abilities and negotiation.

I will choose ETH. (My personal opinion). Some PhD's in my group were getting more than 4000CHF a month. You have many events and nice things going on in Switzerland for students. You can sky in the alps with ETH organize-trips so cheaply!
And as a reputation...I do not have to add anything.

for phd in computer science, you will get 100%
which means around 5100-5300 chf per month, brutto. netto 4000-4200 chf

I will also choose ETHZ, really competitive, good possibilities to take courses, nice city... rather than Bremen. When I studied netto salary was 2700-3000 chf/month but it might depend on the activities that you have to do besides your work, teaching... and the funding source. Go for it!

i would suggest not to bring the salary issue up until you get an offer, but its just me. furthermore, salary should not be the reason you chose one over the other, its the research topic, reputation, resources...this is a phd you are talking about, not a technician position

This is very good advice. Since this is a PhD position, it should be more about the project and improving your education. If you do not yet have an offer and make it seem like you only care about the salary, then you will turn your potential employer off from you.

Your PhD is much more about your professor and your project than about the school and the paycheck. You get the right advisor and the right project and you'll be set for along time even if are at a school with a 'lesser' reputation. You get a demon advisor that uses you as slave labor in order to finish a dying project and doesn't care about your opinion or your future then it doesn't matter if they are a 'legend in their own mind' ETH Herr Doktor Professor.

all this is true, but rather hard to figure out before you actually go into the group and spend some time. from the onset, better look for 1) research topic 2) school reputation 3) productivity and the quality of the publications of the group under question

Hello to everyone!

Thank you very much for your answers that I have received so far, you all are very kind! I just wanted to add a little detail, in order not to be misunderstood. I apologise if I did not make it to get through before. I am not claiming buying a big estate with a phd salary (obviously eheh ), but I have heard that Zurich is one of the most expensive towns in the world, so I mainly would like to know, in case I should be accepted, how much I should expect in order to be able to make a living in Zurich. I mean, mine is not a matter of money, it is a matter to survive/make a decent living in one of these two towns.
As soon as I know whether I am accepted, I will take a final decision.

Thank you all for your attention and cooperation!

I very much agree with the above. However, that does not mean you can entirely disregard the size of the paycheck - or the cost of living, for that matter. There are professors out there (not many of them in Switzerland, though) who pay such a low salary to PhD students that it is simply impossible to survive without an additional source of funding. If you spend fifteen hours a week flipping burgers at McDonalds, your studies are obviously going to be affected, no matter how good the quality of research at your institute.

i recommend comparing those "low" salaries with what the US or other countries' universities pay (factor in the expenses as well) and you will see CH is in much better shape no matter how you look at it

Agreed. One thing to find out is where the professor's previous students have ended up. Did they get good positions, go to industry, drop out? Talk to his current students and to other students in the department.