Snapdeal Interview Experience for Java Developer | 2.5 Years Experienced

Round 1: Coding round which had 10 MCQs based on JAVA and MYSQL along with 4 coding questions. The total duration was 75 mins (15 + 60). 

1. Print strings starting with the given prefix.  
2. Print all leaf nodes of a tree. 

The other 2 questions were lengthy, I do not remember the question. I was able to successfully submit 3/4.

Round 2: 

Coding question: 

1. Print the right view of a tree and dry run it.

Java Questions:

1. Hashmap and it’s working
2. Difference between ArrayList and linked list.
3. Questions on the design pattern. I told the interviewer that I have experience in using factory design and singleton. He started asking questions on singleton pattern like where to use it? What are its advantages? How to make sure that only one instance is created?
4. Questions on indexing in MySQL. 
5. How annotations work in jersey framework? Jersey was asked since I mentioned it in my resume.

Round 3: 

Coding question:

1. A person has to climb n stairs but at a time he can only climb either 1 stair or 2 stairs. In how many ways he can reach nth stair? This is a simple Fibonacci series-based question. 
2. Questions based on jersey framework. How annotations internally work, which I didn’t knew that time.
3. Questions based on table indexing and db partitioning.
4. Write a code to make a custom class as key for a java hashmap. What needs to be taken care in this case?  Questions were tricky. The class he gave me had a list variable too and I did not knew the time that we have to make it immutable too.

Round 4: The worst round

The interviewer had very poor English. He was unable to explain the question and even questions were not to the level of 2.5 years experience. 

1. Suppose you have a customer base of 1 billion, how will you calculate the number of requests to process? How will you limit the number of requests?
2. How to make a method as REST? 
3. What will happen if we write poor hashcode?
4. Questions on string pool.
5. He gave me a query to write department name, along with number of females and males. I did that using CASE for which he argued that Mysql does not have CASE functionality. Hello Mr Interviewer please look this https://www.w3schools.com/sql/func_mysql_case.asp . Anyway, I modified it using IF ELSE which he approved. 
6. How to create a clustered index in MySQL?
7. How to increase data type length of a primary key. Write command.
8. NIO and BIO in java

Apart from 1st 2nd and 8th I answered all and yet the result was negative. 

Anyways, guys do post answer of 1, 2 and 8th in comments.