The city of Dublin is well known for its terrible lack of housing at present. The growing amount of workers from abroad and the many students that every year come to study in Dublin continuously grows faster than the supply of suitable housing. The best you can do is be proactive. Once you are 100% you need to move, whether from abroad or one apartment to the next, start your search!
Due to the lack of housing, landlords and property owners can be picky when choosing a tenant. Bring your work references and previous landlord references if possible. The more you have to show proving you are reliable the better. That said, beware of what you are getting yourself into! Many people take advantages of newcomers; renting places as a “studio” when they can’t even be called a room. Having a roommate is usually a good bet, but don’t become desperate and always choose one you’ll get along with; this way you avoid future problems.