Paytm Interview Experience – SDE 1

I got the chance to get interview for Software Development Engineer 1 post for Paytm Payment Banks office in Noida. I had 1.5 year experience.

Round 1: Technical Round

The first round is a mixture of DS and DBMS questions along with concepts of java and some questions on my projects mentioned in resume. He started with my work experience and projects.

He asked me to create SQL tables to show the relation between user and passport number. An user can have multiple passport number entries due to cancellation or reissuing. He wants me to draw tables writing all fields required, mention keys and relationship between user table and passport table. Further on this, he asked me some MySQL queries on the same DB problem and few are separated from it like find second max salary and count of unique account numbers.

DS questions are Rotten orange problem, binary search code, he insisted me to write code in java. He asked me questions over what technologies I know.

Round 2: Technical Round

In my second interview, he thoroughly went through my resume to ask me different questions on my skills.

• DS question: find minimum no. of platforms required to schedule the trains(arrival and departure time is given)
• Explain about internal working of HashMap in java
• Arrange the students on the basis of marks. (override comparator of sort() method)
• Some java concepts questions: All OOP concepts – polymorphism, inheritance, encapsulation, abstraction, how to achieve multiple inheritance, difference between interface and abstract class, String mutability, garbage collection in java, Singleton pattern (thread safe), factory pattern, multi-threading
• Difference between SQL and NOSQL DB, CAP theorem, ACID properties

Round 3: Managerial Round

The last round is VP round with the VP of the team. He was very friendly. He asked me about work experience about my current company. This round is short one.

1. Tell me something about yourself.
2. Why do you want to switch the company?
3. What are the challenges do you face till now?
4. Which project do you liked the most and why?
5. Team Conflict questions.
6. What are your strengths?
7. Do you have any Location constraints?

Result: Selected