Highly dependent on the area of the department - generally my experience has been less hierarchical than typically associated with my agency, fairly social with a good commitment to teamwork.
Very male dominated, conservative, impression that it is difficult to progress as a woman, as a person with a culturally or linguistically diverse background, as someone who identified as LGBTI. Men's club type thinking is pervasive, very few women in senior leadership positions. Organisation is risk averse and not dynamic, believes it is neither of these things.
Strong commitment to the mission; hierarchical, friendly and supportive, but demands a lot too.
If you enter as a grad, your grad cohort forms an excellent social group. DFAT takes in cohorts of 35-45, so you're highly likely to find people with similar interests. However, because people go off on posting DFAT has a slightly skewed social fabric, whereby people are constantly leaving and returning, and people have significantly different levels of experience. At work, however, almost everyone is friendly, often with a dry sense of humour. In my experience DFAT is very good at teamwork and cooperation. The organisation is quite hierarchical though - work will often have to get cleared through several levels of senior officers.
Hierarchical culture at work, socialising with colleagues happens mainly on Fridays and weekends and there is not a significant amount of mixing with other departments, cooperation and teamwork is generally quite strong in the office but the vibe can be stiff at times which reduces flows of ideas.
DFAT is very hierarchical. Benefits of the graduate program include the social aspect - regularly organise and engage in out-of-work activities.
People at DFAT are professional, courteous and fun to be around. As a government bureaucracy, the fund is a hierarchical organisation, but in my experience people are generally interested in good ideas whatever level they come from. The atmosphere is highly collegial and people cooperates to get results. As a graduate trainee, the opportunities for after-hours socialisation are endless are endless if you're into that sort of thing (and no one puts any pressure on you if, like me, you're not).
DFAT hires some great people and is quite social. The Department is quite hierarchical and there is some work to do on increasing collaboration and modernising the department's work practices. Office hours are standard in Canberra, but much more demanding overseas. As a corporate officer, I feel that corporate work and expertise is somewhat undervalued compared to the core business areas. But things have improved since I started (less than two years) so I'm optimistic about my career opportunities.
DFAT can be relatively hierarchical (but is getting better). Colleagues are almost universally capable, professional, collegial and insightful. DFAT's work is primarily cooperative and team-based. Graduates in particular benefit from a very strong social network.
Bureaucratic, relatively professional compared to the rest of the govt, but not compared to the private sector
I have so far had a positive experience of DFAT culture, and found my colleagues to be approachable and friendly. There is a lot of consultation within sections, but not that much between sections. Socialising among the graduate group is very common. I think the difficulty of being promoted and posted impacts the culture at later stages in DFAT, but as first year grads we are quite insulated from this.