I was sent an email after applying a month beforehand. I was given options for different timeslots through a scheduling website, to which I chose a few, and was then confirmed for a timeslot.
The interviewer was very lovely and knew to ask about the hybrid working straight away. I was told that they operate on 4 days in the office, 1 day at home, but with that day being flexible. The job description only listed it as hybrid working, so the schedule was one of my questions. We ended the interview early as this was too much for me, and they were very kind about it, appreciating that it was better for neither of us to waste our time.
I later saw that it mentioned the 4-day office working in the job description, but it was right at the bottom under the "about the company" section, not in the actual job description part.
The process, from what I saw, was easy, and the interviewer was great. I just wish they had highlighted this dealbreaker sooner.