First had a call with the recruiter who scoped my background and interests and decided for which stream within software engineering was he going to put my application in for. Since I'm more of an interactive, client-side guy, I chose Software engg - Frontend.
Had an hour long phone interview with a frontend engineer , who started with general CS and systems questions, went deep into JAVA (Threads, deadlocks, VM, garbage collections) and ended with some challenging javascript questions, which neede knowledge of javascript patterns.
About a week later, got a call saying I had made it and they were flying me out to Mountain view for the on-site rounds, 'INvitational'. Chose a convenient date.
On their campus, got to know that linkedin holds 'INvitational' for entry-level candidates. It's basically one whole day of interviews and events with their selected set of candidates. The day started off with breakfast, ice-brekers for all the interviewees and an inspirational talk by a senior manager. After warming up, two hour long interviews were scheduled. Both with experienced engineers. One was algorihms - with concept only from standard books like CTCI and the second was web-module development test, where I was shown a certain part of their site and had to write the structure, style it and code the logic. The main thing is to talk through your approach.
After the first two rounds was a long tour of campus, lunch and talk with recently joined engineers about their experience. Spent 2 hours here, but helped calm me down.
The final 2 rounds came after, one was with a very experienced engineer, who showed me a new UI feature he was implemeting on his work laptop and I had to try and code that up. Stumbled a lot here, mainly because I didn't know about how to implement each feature for all browsers/devices. The last round was a manager interview in which I had to talk about a system design (CTCI - esque) and later about my work experience and work style, probably to determine a culture fit.
The day ended by all of us candidates and a few recruters going to a nice sushi place with tons of options. Linkedin surely keeps you well fed.