In your offer letter, it should say what your job responsibilities are. Usually things like “work with stakeholders to develop features”, etc etc. In that off

In your offer letter, it should say what your job responsibilities are. Usually things like “work with stakeholders to develop features”, etc etc. In that offer letter, you need to negotiate so that it says “backend features” and “op will not be required to implement frontend features, which use technologies like JavaScript, typescript, and css”. The act of negotiating this will show you if the company is actually ok with this or you are just being told yes by a recruiter. If you can’t get this, then you are effectively powerless.