Pros
Joining through the YPP (or really any Professional level post) is a great deal. They pay for your relocation, they pay part of your taxes, you have great working hours (lunch is included in the 8 hour workday, so I have always worked 9-5 with a 1 hour lunch break). Teams are diverse, gender is balanced, I'm part of the LGBT community and have never felt discriminated against in the workplace. The work is towards a good cause and impresses people. I find that my coworkers have all been very smart and interesting people who have diverse life experiences. Work/life balance at the UN is probably the best anywhere besides Europe (some of my European coworkers complain they "only" get six weeks vacation). Working at the UN is like working at the US federal government - great benefits, not to stressful (although some jobs definitely are), but we (or at least P staff) make probably double or triple what most people at the federal government make.
Cons
Job categories work as a type of class system within the UN and it is very hard to move between them. So if you have an undergrad degree, don't let yourself apply for G posts. People get stuck in these and never make it to P. My advice is to just apply for P posts - if you're young enough and your country is on the list, apply for the YPP. If you're too old or your country isn't on the list, get a master's and five years' experience working in international orgs and apply for P3's. Don't get distracted by what the job description says - just apply for everything and you'll get lucky if it's meant to be. That said, a LOT of people want to work at the UN so there's really no way to make 100% sure you get in. I've found that generally the UN tends to hire specialists - I studied economics; the people I know who studied international relations didn't get the job and I did. The UN is like any government agency - we hire economists, librarians, business majors, administrators, finance majors, etc. People with international relations degrees don't tend to work here; rather, they work at UN-adjacent NGOs. Another negative is that the UN is a huge bureaucracy. It takes forever to get anything done. But, that's the price of triple checking everything so as not to cause harm so I think it's justified. But it can definitely be frustrating at times.
