I had my round2 almost 2 weeks ago and haven't heard from them since then. So I am assuming it's a reject.
I was given an Hackerrank OA link. I solved 2 of 3 questions (I didn't get the 3rd question).

I was approached by recruiter just after 2 days and I was asked to schedule my interview just the day after. I somehow managed to postpone it by 3 days that too after requesting them thrice that I need a week's time(I really need to learn this. I am never able to reschedule my interviews to a later date).

2 rounds were held on the same day each of 1 hour long. I was told I will be asked for 2nd round only if I managed to pass in 1st round.

Round-1
Was asked about myself. Few discussions on my resume and projects.

Then OOPs questions on copy-constructor, abstract class, interface, difference between C++ and C and also difference between C++ and Java. (1-2 more questions were there I am not able to collect).

Next questions were there on Mysql as it was mentioned on my resume. He asked me difference between PostgreSql and MySql and then was asked to write 2 join queries.

Last but not the least was asked a very standard graph question (slight modification of number of islands).

Got a call for round 2 after half an hour.

Round-2
Intro and questions from resume.

Then was asked to design an instagram/facebook. (If someone can let me know the approach for this question. Please comment.) When we scroll the newsfeed to see the posts, we see posts coming up live. So I was supposed to take those live stream of posts and compare those which were 15 min apart (Here I didn't had to compare the posts literally there was already a function named matchedPosts(post p1, post p2) for that purpose). I had to focus on retrieving the posts and if the posts were 15 min apart, had to call matchedPosts function. Since the posts are coming live hence he wrote an infinite while loop and asked me to implement getNextPost().
I was given info about each post. Which was like this
{
author: xyz
media: asmamsmasmsamsamsam
timestamp: 09:00:01
}

Please let me know about the design question. I thought he was expecting me to approach via thread but not sure. Let me know your approach.

Then few Operating system questions were shooted. Questions on process vs thread, concurrent Hash_Map, virtual memory, Hash_Map vs Map, etc. (I also messed up with this section as I was not brushed up with OS)
After that I was asked to implement a stack from scratch without using any library and to perform few operations on 10 stacks as input is given.