Should a front-end developer know about CMS software like Contentful? Is it essential knowledge to work? I also need to know software such as Google firebase and I cannot find a good answer to these issues. Thanks in advance for your answers.
It isn’t essential unless you plan on working for a job using those specific technologies.
What is essential is understanding the general “front-end” ecosystem, so you can at least understand what you could learn. So knowing what Firebase is good and not good at is more important than knowing all of Firebase. Same goes for a specific CMS like Contentful.
If your looking at jobs for these technologies specifically, yes its more a requirement, but if they aren’t mentioned, just being aware of roughly what they are should be enough.
Good luck, keep learning, keep building