As an aside we were told a few months back that Flight Ops had received over 3000 applications for the FO slots. No doubt it has increased since then after they readvertised.
Originally I understand we were looking for 50 new pilots, although this seems to be a moving target. If you made a reasoned guess that they would interview say 10 for each slot then that is 500 people to invite forward. This equates to only a 17% chance of being called up. If you were lucky to get the job then that is a 2% chance out of the original 3000 applications.
Probably no different odds to any other first time job going and highlights just how few people will get a job once they have completed their training. Good luck.