I am applying for a position for a pre-defined PhD project in Europe and I have been invited for an interview in a few days.

What factors affect the PIs choice in these situations? Are publications or relevant research experience and enthusiasm more important? I have strong grades from my undergrad and master's programs, I presume a strong LoR (it is from a friend of the hiring PI who I did a short summer research stint with), relevant research experience from my undergrad and my short summer research stint, and certainly lots of enthusiasm for the topic. However, I have no first author publications (just a co authored paper and my undergraduate honors thesis) and my master's is not in the same subfield of research as the hiring PI's.