Status : New grad - MS in CS , Top 50 Schools for CS
Interview Date : February 26th 2020

Long post alert, But do read it. It will be helpful for those preparing for Oracle OCI

Got an phone interview via Linkedin the very next week.
Didnt have much time to prepare.

Phone Interview Question
This was a ridiculously different question from leetcode. The question was given a List of words and a input K and a list of characters, return a string with the specified number of unique characters(K) either by using the whole word or not using any character from a word.

Input : a = ["one", "two", "three"], b = ['a','b,'c']
If K = 3, one
If K = 5, onetw
If K = 2 or 4 or 6, you cannot generate an output from the above list as you would break the constraint of either using the whole word(all characters) or using nothing at all. In such a case, you have to talkle characters from another given input list of charcters. The interviewer additionally posed some other constraints such as not using a for loop, etc. However, the interviewer was really helpful in getting me to the algorithm and helping me to code it.
To be honest, it took me around 30 mins to understand the question and the constraints he posed.

The phone interview was set to 1 hr but it extended to 2 hours as he wanted me to solve the problem no matter what. I was really getting stressful at this point but with his help I was able to come up with an algorithm and code it up in coderpad. It ran successfully for all test cases. Not one behavioural question. He didnt even ask my name in the first place. From the first minute till the end of 2 hours, it was only about this question.

I really did poorly and honestly wasnt expecting a call back. But Magically, I got a call back the very next day asking me to schedule for an onsite interview within 2 weeks.

I was happy and set it up with 10 days to prepare. I prepared about 85 Oracle tagged leetcode questions and a bit of OOD and System Design from ***

Every coding round had 2 to 3 behavioural questions.

Round 1 :
Given a file structure, convert it into a tree
Eg : If root is the main folder under which you have folders like src, js, etc and under each sub folder you may have many other sub-folders. Given this structure return a tree.

I was a perplexed initially but I was able to solve the problem withing 40 min. I felt like I nailed the interview as I have never seen a question like this before but still solved it to perfection. I am pretty sure the interviewer was also satisfied.

Data sturcture used was HashMap<String, List> to get the child of every parent and then used recursion to convert it into an n-ary tree.

Round 2 :
Given an array, return boolean if it is skippable
Eg : [1, 2, 3] output : true, [1, 2, 4,5, 16] return false

Came up with a brute force recursive solution within 10 mins and was asked to optimize it with memoization and DP. The interviewer expected me to write all the 3 codes and I was able to do all 3 within 40 min again. Discussed time and space complexities. Again, I felt like I nailed this round as well.

Round 3 : Hiring Manager Lunch interview - 90 mins
Fully behavioral questions. Felt like it was an okayish round as I did not fully answer what the manager was expecting. He gave me suggestions on how to act in different scenarios.

Round 4 :
This was a shocker as I saw the same person who took my phone screen came back again to take my interview. I was like why me. This time he bought a deck of cards and shuffled it and asked me to write code. I was like "R u serious? " in my mind of course :P . I told him just swap the list of String he would give me. He was like anyone can do that but I want you to do exactly what I did while shuffling. Cut the deck into two, Drop some cards from left then drop some cards from right hand and repeat until there are no cards left in my hand. He posed some constarints this time as well. I do not want to explain it as it will take some more time

But Again he was helpful and I did write a part of the code. Unlike phone screen, he couldnt extend it to 2 hours as the next interviewer was knocking on the door. You might be the leetcode expert but I am pretty sure you could'nt have solved with all the constraints in 1 hours. It was an okayish round.

Round 5 : Bartender round
Again a lot of behavioural questions, This time I did really well as the hiring manager gave me suggestions on what they expect. Used all those suggestions in this round. The round went really well.

Overall, After the endurace test (about 5 round and six and a half hours of interview), i was pretty sure I would get an offer.

But unfortunately, I got a mail from my hiring manger(not my recruiter) stating the same:

"We did receive good feedback in general but some of the folks thought he may need additional coaching from peers. At this time, we already hired junior developers so our team is looking for developers who can work independently. He may be able to apply back once he gains more experience.We do not have an IC2 position open at this point of time under my OCI subsystem."

I was what the hell!! You knew I was a new grad. You invited me for a phone screen which i did poorly. you could have seen my resume and rejected at that point of time. But you invited me for an onsite of 5 rounds which i did really well comapred to most of those IC3 so called experieced hires who were hired. I was really disappointed with the feedback though I had a backup full time job.

Yes, The whole process was smooth. All the interviewers were really friendly and helped me whenever I was stuck.
And the phone screen guy especially who wanted me to solve real world problems, Thanks to him lol:P
I was also happy that I was able to solve sums that were not in leetcode and sums that I have never seen before.

But none of those matter as I did not get an offer. Life is so random. Just pure luck.

Thanks if you have come so far in reading such a long post. All the best as well!