Pros
I want to start my review by pointing out that Milliman in Seattle is broken up into different departments based on their service. These departments are Health, Employee Benefits, Corporate, Life, etc. If I recall correctly, there are about six or seven separate orgs under the Seattle banner. Your mileage may vary. My position only required 37 hours of work per week, which was really nice. People around the office, more often than not, were personable and willing to have a chat about work or otherwise. As a "support staffer", I was able to get my hands on all parts of the business. I worked on many different business functions and worked directly with the Equity Principals on projects for the firm which was great exposure. This place is definitely the pinnacle of companies for those wishing to be an actuary. They have pretty good benefits but the crown jewel is their 401k (13% matching after a year, if I remember correctly). The 401k is an unbelievable benefit if you're considering staying with the firm for your whole career. The company will pay for professional development for actuaries. There is a very relaxed culture and the ownership sponsors many happy hours for the whole practice.
Cons
I left Milliman a few months ago and wanted to wait before leaving a review so as to not have my emotions dictate what I write. As a support staffer, I felt and witnessed a lot of disrespect from the consulting staff towards support whether this was the IT team, the office administrators, or otherwise. As Milliman, in my practice, has a rigid, stepladder structure for actuaries, there were some employees who would get a newfound sense of self-importance when they achieved the next level. This would often result in a considerable amount of disrespect shown to the support staff. There were a number of confrontations from managers that would leave admins in tears. While this was handled post-facto, promotions were very evidently determined by actuary skill where managerial skill was not very strongly taken into account. There was no feedback requested by support staffers before deciding who to promote. The Equity Principal (an owner of a practice) who was in charge of managing the admin staff seemed to have an attitude of suppressing issues that arose from said staff. Complaints about managers who treated admins with disrespect were devil's advocated and any concerns about the way things were run procedurally were dismissed. When I pointed out that I was being severely underpaid for a business analyst in Seattle, I was told to "go out and get an offer letter from another company" to justify a raise. In the same vein of compensation, there was a culture of extreme frugality toward support functions. The servers that hold all the files and allow the analyst to perform extensive calculations became obsolete the year before and there was pushback from the ownership on replacing them. When I asked for a professional certification to be paid for by the company, the way actuarial analysts are, I was rebuffed and told to consider pursuing it on my own. There was almost a paranoia from ownership about training staff who "might just leave after they are done." This sentiment would leave more competent workers feel as if they were deteriorating and would leave less competent workers no avenue to better themselves.