It's been over 13 years since I interviewed but I can't imagine the basics have changed very much.
There will be an ATPL type exam with questions about density altitude, the ITCZ, handling big airplanes, that type of thing. There will be probably be the usual "games" and group tasks. Just follow when it's time to follow and lead if the opportunity presents itself. Be sure to have a diplomatic and soft approach with your potential co-workers, especially if they're from cultures other than yours. For the interview itself rehearse your answers to the typical questions of tell us about a time when....etc. Learn something about the airline and its principals, islamic culture, dubai life. Have one or two thoughtful questions for them at the end.
And then there's the sim. Yeah you ultimately have to be able to fly so practice by taking the automatics off every chance you get. And when you're in there make good decisions. I'd say that's almost as important. For example if you're way out of position to land then throw it away, go around. They'd way rather see that then somebody go way unstable and land under marginal control halfway down the runway. Probably best not to crash.
I'm sure the recruiters will dangle the carrot of an upgrade in X number of years, and maybe they even believe it, but it will probably take longer. Know that going in. But look, if you're one of the guys with the bare minimum hours (what is it now anyway, 2500 with 2000 jet) then you're probably around 30 years old or younger so even if your upgrade takes 5 to 7 years what will you really have to complain about? I hear a lot of that on the line from 3000 hour pilots in their late twenties and I have zero time for it. Their worst case scenario is to become a wide-body captain on
something by the time they're 40, probably even younger. From where I sit that's a damn good deal.
Talk to everyone you know here and discount their optimism and their pessimism by some factor - the truth is in the middle. Dubai and Emirates is what you make of it. It's true that it's not what it once was but it's still a good job and if you actually are a 2500 hour pilot it's a
damn good job. Just keep a sense of haha, accept that the airline will always do whatever it wants and if it doesn't violate your bottom line you're good. Otherwise vote with your feet.
Good luck!