COVIAM Interview Full Stack Developer (Experienced)

Round 1: 1 hr –  25 Ques

1. Aptitude test – includes (Work & time, Speed and distance, Probability, Reasoning)

Round 2: Coding Round (1 Hour)

1. Given a balanced binary tree. Write a function to print the sum of mirror image nodes in inorder way.

For ex –

            15
        /      \
      23        25
    /   \      /   \
   4    9    21     28

Output of the program will be: 28+4, 23 + 25, 9 + 21, 15 + 15

2. Consider the dial pad with the following layout

1            2            3

4            5            6

7            8            9

#            0            .

Phone number generation can start with any number except 0

Next possible number after the number selection should be either on the horizontal line or vertical line

Generate all the possible 10 digit phone numbers, please note that the consecutive numbers should not be considered.

Ex: if the number selected is 1, then next possible numbers are 2, 3, 4, 7

If the number selected is 0, then next possible numbers are 8, 5 and 2

Starting with number 1, two of the possible phone numbers: 1212131313, 1417131213

Round 3: F2F Round (Technical)

1. They will ask you about your product and architecture questions.
2. Implement your own stack.(Code for push, pop and peek while validating underflow or overflow constraints)
3. Given a string “Welcome to new year”. Tell the most repeated number and some more scenario based questions- O(n)
4. Given a linked list, find the kth node from last.
5. I worked on rest services so asked about rest calls.
6. Database joins – retrieve all the students whose have address(student and address we have two tables)
7. Monolithic and micro services difference

Round 4: F2F Round (Technical + Managerial rounds)

1. Internal Implementation of Hash Map (Hash code and equals methods)
2. How to synchronize hash map methods. It will be completely thread safe or not?
3. Implement Synchronized Hash map of your own.
4. Difference between error and exception. Various types of exception. (Exception handling questions).
5. Database – Second largest salary of an employee query, multiple joins.
6. I have worked on hibernate so asked hibernate question. Write code for @ManyToMany join implementation of Student and Courses.
7. Puzzles – Let’s say we have 25 horses and we have five tracks. How many min number of attempts we required to select top 3 horses out of them. Constraint is we don’t have any timer.

Round 5: F2F Round (Technical round with Co-Founder)

1. Write a pseudo code for the given situation. We have a hotel with multiple floors. Let’s say floor# 1 have 10 rooms(numbered from 1, 2…10), floor# 2 have 5 rooms(numbered from 11, 12…15), floor# 3 have 10 rooms(numbered from 16, 17…25), floor# 4 have 5 rooms(numbered from 26, 27…30) and so on. Let’s say some room# is given by user, we need to find:
2. The floor# on which it exists.
3. Location of the room on that floor.
4. We have a stove burner which have capacity to roast two breads single side on same time and it takes 5 min to roast them. We have to roast five breads from both side. What is the minimum time it will take to roast all five breads.

Then I got selected and have one more round with CPO regarding package.