Adobe CS1 || Worst Hiring Experience including interviewer and HRs

I applied for the CS1 position through Adobe's career site. About 15 days later, I received a call from HR to schedule an interview.

Round 1 (DSA)

The first round focused on Data Structures and Algorithms. I was asked a variation of the Max water trapped problem. I was able to code the solution efficiently, from a brute-force approach to the most optimal one, within 20 minutes, including a proper dry run. The interviewer then asked me to write edge cases, even after I explained that my code inherently covered them. I eventually added a specific edge case condition, but the interviewer drilled me on C++ internals related to vector size checks (e.g., v.size()<=2 to v.size()-2<=0), which I found challenging to answer point-by-point.

Following this, I was given a Design problem. I needed to design three APIs: Get(id), Add(id,name), and Delete(id), all requiring O(1) time complexity. I proposed a Hashing solution, but the interviewer disagreed, citing potential collisions that could degrade performance to O(n). Overall, the interviewer didn't seem satisfied with my performance in this round.

After this, there was a silent period. I tried contacting HR multiple times. Eventually, she picked up, and I explained the situation. She agreed to move me to the second round.

Round 2 (DSA)

This round was much better. I had a very good discussion with the interviewer. I was asked to Reverse words in a sentence, carefully handling spaces. I solved it efficiently in exact O(n) time by iterating from the end of the sentence. Towards the end, the interviewer asked a time zone-related question: 'Suppose you are in India and the time server is in the USA, how would you overcome latency?' I proposed multiple approaches, and the interviewer seemed satisfied with my answers.

Round 3

I joined the call on time for the third round, but the interviewer never showed up, even after waiting for almost 15 minutes. I tried calling HR again, but she wasn't picking up. After some time, I received a call back and explained the situation. She told me she would call me back in 5-10 minutes and asked me to leave the meeting, which I did. I waited for an hour, but no call back, so I called again, but still no answer.

The next day, there was no response until evening. I called again, and HR picked up but astonishingly asked, 'Who is this?' It was truly disheartening, as it indicated they hadn't even processed my status or knew who I was. I re-explained the entire situation. She said they would re-conduct the round, and I'm currently waiting to see how it goes.
I wish for luck that the hiring team responds in a timely manner!