I was contacted after my university's career fair.
Initial phone screen with recruiter, then two technical phone interviews with a third party company. These were pretty standard questions: OOD, inheritance & polymorphism, factory & singleton patterns, binary search, hash table basics.
Subsequent on-site interviews lasted one full day: Introduction to the product and architecture, 3 technical 1-on-1 interviews and 1 non-technical 1-on-1 interview. My experience with all of the recruiters, interviewers and the entire team was very pleasant.
Technical interview questions included: Design a bounded queue, sort an array in place, and a lot of architectural/design questions tied to prior projects, along with a discussion of performance and process tradeoffs among design choices.
After the interviews, there was a 2 hour coding project: write a program that reads a configuration of chainable filters from a spec file and applies it to a large amount of text. Interview questions and even the coding project were language-agnostic, which is nice and shows that this company is asking the right type of questions (ie, cultural+conceptual rather than encyclopedia questions about language-specific feature xyz). In the end of the day, we got to sit down with and talk to Jeff, Kontagent's CEO and founder, which was great.