Three questions on (finding) permanent positions in France I've a few questions about permanent positions in the universities in France. P.S. if you think question # 3 deserves to be asked as a separate question, please let me know, and I'll do so. As far as I'm aware, there're three main types of permanent positions there: (are there more? If yes, please let me know then!)

Maître des conférences: (word-to-word English translation: master of conferences, MCF for short) which is a teacher-researcher position.
Chargé de recherche: (word-to-word English translation: charge of research, CR for short) which is a researcher's position, very coveted, with teaching being optional. Offred by CNRS.
INRIA permanent researcher's position: very coveted, offered by INRIA. Research-only like the one at CNRS.

My questions are:

Are CR and INRIA permanent positions necessarily more competitive than the MCF ones? I do know that MCF's are also not easy to get by any means, and I myself have neither, but I'm only asking. My respect to anyone in their MCF positions, and this is not an attempt to belittle anyone by any means!
If you get an MCF position, is it possible to &quot;switch/transfer&quot; to a CR one after a year or two? I wrote the two words in quote, because I don't even know if that's a meaningful or possible transition.
(I can ask this as a separate question if you like, just let me know!) Is it possible that as an MCF, you can do the teaching in the math(s) department and research in the computer science department? This question is very specific to my case, as I've an unusual CV, where I did my PhD and taught for and was a teaching assistant  during 5 years for several courses in pure mathematics in the US (not in France), but I transitioned to statistical machine learning using heavy pure math machinery like differential geometry and functional analysis. Now this makes me naturally eligible to do research in the Computer Science (CS for short) department, but after having a few initial interviews, I'm getting a feeling that I'll need to teach CS courses like data base etc., which I've no idea about. On the other hand, I'm not a pure mathematician any more (although much of my applied research use heavy pure math), so I don't know even if they'll consider my CV? This is why I ask this question. If the answer is a resounding no, then I'd appreciate it if you could please be so kind to let me know how I can apply for an MCF position given my trajectory, where I can teach pure math(s) (and selected stats, e.g. probability theory, statistical machine learning, statistical inference etc.)

I greatly appreciate any help and your answer!
Thanks a ton in advance!!
It's hard to give a general answer, but yes, they are more competitive. CNRS/INRIA positions are nationwide competitions (in the sense that a MCF is tied to a university, while a CR is tied to CNRS/INRIA which are national institutes, so a CR can request of change of assignment and move to another French university rather easily). They are also intrinsically more attractive than MCF positions: you get no teaching duties for the same salary, and you can still teach if you want to so long as the department has some teaching vacancies not filled by permanent teaching staff -- and they almost always do.
It is technically &quot;possible&quot; in the sense that there is no legal obstacle to it. The only way to do this is to get your MCF position, then apply like everyone else to a CR position when it opens. Maybe things are different in CS (I'm in math) but I do not know anyone who has managed to do it, or even expressed the desire to try. Recruiting committees know that giving a permanent position to a postdoc is life-changing, while giving a permanent position to someone who's already got one is only a change of assignment. They heavily lean towards the first.
Yes, it is possible. I have several colleagues who do it.

Just a note, the positions offered by the CNRS and the INRIA are the same, &quot;chargé de recherche&quot;, and have the same statutes. It's just a different employer. CNRS and INRIA are both the same kind of legal entity, an EPST.