To expand on the other answer, we usually have monthly vacancy bids (unless hiring stops, which is unlikely now but happened during covid). With the duration of initial training, and depending on the time of the month you start, you will have at least 2-3 bids before you become a line pilot. With attrition, upgrades, base growth, and people switching around, even if you don’t get FLL the first bid, it’s very likely you will have it before you finish OE.