First Round:
It was an online test consisting of 4 coding questions, all of which were of easy and moderate levels.
- Given a string “xoooxoxoxoxo”, which consists of ‘x’ and ‘o’ only. If the number of ‘x’ and ‘o’ is equal, return true; otherwise, return false.
- Given two strings, str1 and str2, check whether rearranging the characters of str1 can result in str2.
- Given a string that consists of symbols, numbers, and characters, for example, “A man, a plan, a canal: Panama!!”, find out whether it is a palindrome or not.
- We were given a 9×9 sudoku grid and had to return where the inputs in the sudoku were invalid (where the numbers from 1 to 9 are repeating in each of the 9 3×3 grids). Return the number of 3×3 grids where the sudoku is invalid.
Second Round (Technical Interview Round-1):
This was the first technical round where I was asked about everything mentioned in my resume. Starting from projects in depth (I implemented authentication using JWT tokens, asked briefly), I was asked about each project, how it was implemented, which technology was used, and about GitHub. The interviewer also helped me when I got stuck. I was asked questions about computer networks, like URL, DNS, classes, and why we need the OSI model. I was also asked to write two SQL queries about joins.
Afterwards, I was asked 2-3 coding questions, such as the valid parenthesis question from LeetCode, to calculate the value of the string “2*3+5/5” (BODMAS applies and brackets are given to differentiate the operators). The output should be 7. I was asked to write the complete code for this problem, and the last question was to write the code for a palindrome string.
Third Round (Technical Round-2):
The interviewer was very kind and helpful. This round started with the questions from my online test, so I explained them all. Then he asked about GitHub commands, as I had mentioned GitHub in my resume. After that, he asked about my project, like why I used MongoDB, why I did not use an SQL database, and the difference between SQL and NoSQL databases. Then he asked me two DSA problems based on arrays and strings.
- I am given an unsorted array consisting of positive and negative integers. I have to find the first missing positive integer from this array.
- Given a string “AABCDACD”, return the string that consists of the first non-repeating character corresponding to each character in the given string. For example, given str =”ABCDAABC”, the output should be “AAAABBCD”. For i=0, the first non-repeating character is A. For i=1, ‘B’ is also unique, so the first non-repeating character is also A. For C, return A. For D, return A. But for i=3, ‘A’ is now repeated, so ‘B’ will be the first non-repeating character.
Fourth Round(HR):
I was asked simple questions about my family, and where I live. HR questions like – what are the top 3 things you want in an offer, your strengths and weaknesses, and achievements, have you participated in any coding competitions hackathons, or group projects?
Finally, they declared the results after 4 days and I was selected for the role.