Total 6 rounds (all happend in a single day):
1st Round (1 hour):

1. Deep dive into C and C++ basics. Pointers, bit manipulation, string manipulation, 2D and 3D dynamic arrays, Questions on arrays, strings (1 hour)
2. Basics of Networking (OSI layer)

2nd round (1.5 - 2 Hours)

1. All variations of linkedlist (cloning, finding loop, finding the intersection point, deleting the middle node, etc). Total 6 questions asked on Linked list
2. Write full class structure of binary tree and write insert operation.
3. Deep dive into OS concepts:
   i. Memory management.
   ii. Difference between process and threads.
   iii. Segmentation
   iv. Paging
   v. Memeory layout in programs
4. Questions on networking:
   i. ARP protocol.
   ii. How packets travel from source to destination
   iii. TCP and UDP protocols.
5. Questions on linux OS: inode structure, Daemons.

3rd Round: (~1 hour)

1. Implement circular queue (push and pop operations)
2. Deep dive into OS concepts:
   i. Critical sections.
   ii. Mutex.
   iii. semaphores.
   iv. Race conditions.

4th Round (SDM round 1.5 hours)

1. All types of behavioural questions.
   i. Why you want to leave the company.
   ii. tell a time when you had a conflict with a team member.
   etc
2. Deep and detail discussion on Projects. (The discussion was so detailed that i had to explain our whole code base)

5th Round (Senior Manager 1 hour)
Same as SDM round
He explained me what Aruba does, what is expected from me.

6th Round (HR round)

1. Basic behavioural questions.
2. Expected Salary.
3. If comfortable with relocation
4. Company culture

Read about compensation here:
https://leetcode.com/discuss/compensation/1874112/Aruba-Networks-an-HPE-company-or-System-software-engineer-2