I've got call from Goldman Sachs for Senior Software Engineer profile. As of now two rounds happened Hackerrank and Coderpad round. Both rounds are cleared and awaiting for further rounds.

Hackerrank round:

1. Run length encoding question. ex. there is a string Aaabccdaab print output as a3b1c2d1a2b1.
2. Count Possible Decodings of a given Digit Sequence. ex. there is a string "121" so possible decodings would be "ABA", "AU", "LA"

Coderpad round:

1. There is file containing lots of logs from apache server in specific format such as "ip - log details- date". I need to find all those ips whose frequency are same. i.e. find all frequent ips even if they have similar frequencies.
2. Given a 2-D String array of student-marks find the student with the highest average and output his average score. If the average is in decimals, floor it down to the nearest integer.
   Example 1:
   Input: [{"Bob","87"}, {"Mike", "35"},{"Bob", "52"}, {"Jason","35"}, {"Mike", "55"}, {"Jessica", "99"}]
   Output: 99
   Explanation: Since Jessica's average is greater than Bob's, Mike's and Jason's average.

as follow up i was asked to calculate higher average in case of negative marks as well. I was also asked to floor down the highest average score to nearest integer.

I've got positive response from both rounds and will post for other rounds as well.

1 week later I got the call for 3rd round unfortunetly i got rejected in this round. I was asked 3 questions which are as follows:

1. There is an array of strings and a prefix string and I was asked to find all those string which starts with that prefix string. so I gave standard linear scan method so then interviewers asked for more optimized solution. Then I gave Trie data structure based solution which they accepted. but later on they did follow up on the same on which implementation wise i got confused.
2. There is a Max Heap having some numbers and I need to find Kth largest number from the max heap and compare it with another number n and return some response where numbers are equal, lesser or greater than the Kth largest number. I gave wrong heap implementation and got struck in this one.
3. Balance paranetheses. I gave stack based solution then interviewer asked to solve without using extra space.

Result: REJECTED.

I've overall 4 years of experience in backend development. One should be fast enough and quick thinker for the approach and should have great implementation experience in data structure.

Anyway next time. Hope it will help someone !!! :-)