It depends on the principal honestly. In our case, our principal is very loyal to those that work for her or the district. Typically she has hired those individuals who have subbed and/or worked in title positions. In this case, she hired basically a new teacher who had only subbed for 1/2 year... a relative newbie. Ok,OK... I gotta confess. The gal that we hired for the 5th grade position was my student teacher. She student-taught for me in the fall, finished in mid-December & graduated, got married in mid-January, filled my position for 8 weeks while I was on maternity leave at the beginning of February, and finished the last nine weeks of school as a "regular" sub for our district. Whew... that was a long sentence! "H" was the MOST awesome student teacher EVER!! That's why I asked her to stay in my room in February. I picked her over a couple of retired (great) teachers who were willing to do the long-term for me. However, hers is not a typical story. She knew the curriculum as she'd experienced nearly the entire year of it with my room except for 1.5 weeks in December as well as the months of April & May. The reason I am saying that it is not typical is because typically our principal hires those that have been in our title teacher positions. Out of the last four positions we've had open, she has hired two title teachers, my student teacher and a gal with 16 yrs of experience at all grade levels. (The later gal had a husband who was hired by our district as a teacher of the "at-risk" kids and who also does a bunch of coaching.) I think that anytime you have a "toe-in the-door" by being in the system already, it helps.
Good luck to you...