I was initially contacted by a member of HR through email. They asked for three writing samples. A few days later they asked me to fill out an online application form that required a detailed history of work and education along with salary requirement, strengths, weaknesses, and so forth. A few days after that, HR emailed again to arrange a brief screening interview that lasted about 30 minutes. It was just a brief recap of the job responsibilities, location, the hiring process, etc.--basically just making sure the job was what I thought it was, and making sure there wasn't anything obvious that would disqualify me. Then they arranged for me to come in to take a technical writing test.
The test was supposed to take 2 hours, but I took 2 and a half hours. They gave me a large stack of papers, a pencil, and a pen. The entire test was written, with just one question where I got to type it out on a computer. About a third of the test was just basic grammar, spelling, and editing. There were some fairly difficult and devious questions, but with my background in proofreading and editing it wasn't bad at all. There were several sections dealing with rewriting for clarity and concision, which was again fairly difficult but not too bad. There were two technical diagrams that they asked me to explain as best as I could. The last question asked for a comparison of two writing samples with an explanation of how to change one to better match the other. It was a pretty comprehensive writing and editing test. I was worried about taking too long, but I got an email the next day saying that I had done well and that they wanted to schedule the next interview.
This interview took about two hours. The first hour was spent with the hiring manager in charge of the writing department. She asked a lot of detailed questions about my application form, resume and cover letter, clarifying my experience and abilities. She asked what I like in a manager, what were my weaknesses, how do I stay organized, what would my former managers say about me, what one thing would I like her to remember about me, among other things. The next hour was spent with three members of the writing team. They gave a lot more details about how the job worked, what the department was like, and grilled me in more detail about my experience and abilities. They had copies of my resume and application form as well. They seemed to focus a lot on communication skills--how do I deal with stress, how am I at mediating conflict, have I worked on cross-functional teams, and so forth.
I also know that two or three people from the company checked out my LinkedIn profile before the interview, so make sure that is up to date before applying.
In the end, I felt pretty good about the interview, although I knew there would be some challenges since I didn't have any direct experience with technical writing. I did know that I had the capacity, and I had a lot of related experience and a solid technical background. From what the HR person told me, I was probably in the top 3 candidates for the position, but in the end they did not select me. If they had, there was supposed to be one more interview with a senior manager and/or vice president--mostly a behavioral/personality interview, I'm guessing.
I got really good vibes from everyone and was really excited about the job. The atmosphere was relaxed, yet professional. The offices were very nice. The members of the writing team told me they loved their manager (of course--but they really seemed genuine) and that their favorite part of working there was the great people.