I cant speak for all line, but for the ones I know, there aren't really job postings. You apply for a position and go through all the paper work and then they place you on a ship when they have space. My paperwork for
DCL took months, but for Royal it only took a couple of weeks because I already had most of it and it was pushed through fast because i had years of experience.
Once all your paper work is done, then you wait for a ship, depending on your position, this could take days or it could take months. I actually had a ship before all my paperwork was done for Royal, so my start date was pushed back.
For applying for a job on a ship, most positions will use a recruiter in their country, and then there's different recruiters for different positions. Some recruiters will do multiple lines and place you where they think is best for you, others just work with one cruise line.
Cruise line are almost constantly recruiting for most positions so they have people when needed. Like if someone unexpectedly goes home because they get sick, or quit of get fired.
As long as you're not fired then you're given a return date and ship at the end of your contract for the next one.
DCL never allowed it, but with Royal if you want a break then as long as you want to go back within a year, you just let your scheduler know and they'll get you on a ship.
If you want to change positions then you either have to do that onboard and it's based on performance and how many contracts you have done, or you have to quit and reapply for the other position.
Some jobs within the same department are more desirable and seen as a step up (like the pool side bar to coffee shop) so they'll be based on performance. If you want to change position within the same department it's a lot easier like youth staff to cruise staff.
(Dont worry, non of this is confidential and most of this info could be found with a few google searches. I'm not important enough to know the confidential side of the recruitment process haha)
As for going back I'm 50/50.
I want to, but I've wanted a life on land for a while and this is probably the push I needed. However, while i am looking for a job, they're hard to come by atm and a lot of competition so if i get an offer to go back before i get a land job, I'll probably take it.
I did have a job in a supermarket for the lockdown, but now that's eased and those shielding are back at work that's finished now.