Who your friends are can play a significant role in finding a job. Unfortunately the importance of social circles is under rated when looking for a job. A lot of people do find jobs because their friends recommended them or made them aware of a role. However, getting a job because a friend recommend you tends to be more common for entry level positions.
If you are looking for a new job don’t be afraid to talk about it to your friends. They or someone they know may be aware of a role you are looking for. Usually, at the very least, if someone recommends you for a role you will get to the interview stage.
If you have just arrived in Dublin it can be frustrating to hear someone got a job because they knew someone working at the company. You need to make expanding your social circle part of your job search. Luckily in Dublin there are a lot of events being organise to give you the opportunity to meet new people. Meetup.com & Facebook group would be the most popular and are great ways to meet new people. You could also join local sports teams or organise your own event for people new and not so new in Dublin.