I got an interview through a consultant. They took weeks to decide on interviewing me.
This was odd considering I was an exact fit for the job profile, I have very strong experience relevant to this profile.
I had informed of my current salary in advance, and also at every occasion when I was asked. This will be relevant later.
My first technical interview was in person with the Head of RSP team. He remarked more than once that my resume was very strong, and cut short the interview, which was scheduled for 4 hours, to 1 hour because he was satisfied with my answers. He recommended me for the next level, which was with a gentleman in the US, over Skype.
The Skype interview went well too, and was more focused on my previous work in the field. It was broadly technical, but more around projects and less equations.
After all this, the least I expected was a formal offer letter. The lead HR called me to ask details of CTC and informed he would update me in 2 days. Then, there was no response. HR now concluded that my current CTC was too high, something that they claim they were not aware of before the interview (I came to know later).
This was extremely unprofessional, a waste of my time and effort. The HR simply choose to ignore my and only called me back later on the insistence of my first interveiwer. He then made a verbal offer of ~40% lower CTC! I was surprised and declined.
I did expect a lower offer, however, not this low (I simply assumed HR was aware of my CTC and then decided to schedule the interview). They were careless enough to waste my time and not even make an offer to a candidate that was an exact fit.