PayPal Interview Experience for SDE -2 (3.4 Years Experienced)

Hi All, Hope everyone is doing well. I’m sharing my experience with Paypal. 

Round 1(HackerEarth Test): 2 questions 1.5 hrs 

1. https://www.hackerearth.com/problem/algorithm/beautiful-numbers-05de0f51-101121ca/
2. Based on 2D array

I solved both of them one is partially and other is fully.

Round 2(DSA Round)

1. Left View of Binary tree
2. Minimum swaps required to sort the array.
3. Count pallindrome substrings.

I have given optimal approach, with fully working code.

Round 3(Java Round): Discussed Project architecture 

1. Design your own hashmap .
2. Two strings are given minimum swaps to make the two strings equal.
3. Check if a tree is BST.
4. Questions from Executor framework and JAVA 8.

Round 4(System Design):

1. Discussed Project architecture
2. Design a FASTAG system.
3. Code for singleton design pattern.
4. Consistent hashing principle
5. Row having maximum number of 1’s in 0 and 1 array (2D Array ).
6. Questions from Spring Boot( Spring batch, Spring AOP)  and microservices(Service discovery pattern, fault tolerance).
7. Questions from SQL (Joins, ACID properties ).

Round 5(Techno Managerial Round):

1. Discussed current project and some behavioral questions.
2. Asked to design a messing system.
3. Egg drop problem (Dynamic programming )
4. Reverse linked list into k groups.

Tips:

• Be strong with the coding part (DSA), 
• They will be asking for fully working codes, 
• Try to give brute force approach first then try to optimize it, if you give optimized solution in starting then there are chances that your question might get modified.