I had applied to the job on LinkedIn, I got a really fast answer in less than 48h, and a call scheduled 2 days later with an HR in Paris.
First of all, she kept calling me by the wrong first name and talked 70% of the interview ({Wrong name} + 4min talking followed by 3 questions) and I realized at the end of the interview when hanging up that I had been so focused on answering the questions that I had not corrected my name.
Second, it appears that their internal recruiting process is different that was is displayed on LinkedIn. They have several postings with different seniority levels when in reality they receive all the applications in 1 inbox. I was told this rather rudely in the middle of my interview ("Oh, you know, we don't care what you applied for"). Hm, then at least please mention it somewhere. It can really be confusing for the candidate.
Third, it seems like they are really growing fast (kept telling me how I probably couldn't handle the Aircall growth).
Fourth, she tried explaining to me what an engineer should be, and how their software dev process is really optimized and that all I had learned before was without value and "Aircall would probably bring {me} more than I would bring {them}" (not kidding, this is a quote). Rudeness set aside, let's say I would have expected her to actually listen instead of cutting me off in the middle of the sentences assuming she knew what was coming next, when she actually didn't.
All in all, this was the rudest interview I ever had and I am so glad not to be working for them. I would have been interested in talking with the software team, to see if they were as perfect as the HR made them sound like, just curious.