I have an experience of 4 years in Java development with service based MNCs.
Interview was average, two online rounds of aptitude and C.
Difficulty level of C aptitude quiz was 2/5, and aptitude was 4/5. (5 being the hardest)
After the two rounds I had 4 technical interviews + 1 HR round, that took a full working day (~8 hours which included lunch)
In the interviews, they mainly focus on puzzles and problem solving rather than programming.
This is Software Engineer (WBT profile), hence I wasn't asked to code or wasn't tested on my knowledge of Java/C language.
I was told to write standard simple programs for linked lists, arrays, string manipulation with minimum complexity. (Repeatedly told to reduce complexity to O(n) )
Apart from that be prepared to write test cases for any functionality/thing etc.
You will be asked 2/3 puzzles in each round, be prepared.
P.S This profile is a mixture of Black Box and White Box testing.
If you are from testing background then only this profile would suit you.