Ask HN:Is it worth to learn RabbitMQ as a junior back end developer?

I guess so, but that's a weird question. It's not even a programming language and you can learn most of those in a week or so. It's just a simple library, learning everything about it should take max few days. You can probably learn it as you go whenever it becomes necessary.

Yes, absolutely, message queuing is an important part of back end architecture. If you happen to use python, "Celery" is an easy way to start using "RabbitMQ".