💼 PayU Interview Experiences – Intern + Backend + Frontend (Selected ✅)

🔹 1. PayU – Software Developer Intern (Selected)

✅ Key Technical Questions:

🔗 DSA:

1. Reverse a Singly Linked List

   • Explained pointer reversal approach and implemented it.

2. Implement Binary Search

   • Walked through divide-and-conquer technique with code.

3. Merge Two Sorted Linked Lists

   • Described merging logic and pointer movement in sorted order.

🔗 Java Programming:

4. super keyword in Inheritance

   • Explained its role in accessing parent class members.

5. Improving Design with Abstraction

   • Shared examples of how abstraction leads to clean, scalable code.

6. Garbage Collection & Memory Leaks in Java

   • Covered JVM’s automatic memory management and causes of leaks.

7. Checked vs. Unchecked Exceptions

   • Explained with real examples.

🧑‍💻 Questions contributed by: Aman Shukla

🔹 2. PayU – Backend Developer (Intern/FTE)

✅ Interview Process Summary:

• No Online Assessment – Started directly with technical rounds

🧪 Technical Interview 1 (45 Minutes):

• 2 Medium-Level DSA Questions
• Basic Backend concepts:
  • SDLC (Software Development Life Cycle)
  • SQL query

✅ Cleared and moved to the next round

🧱 Technical Interview 2 – System Design Focus

• Discussed:
  • Batching logic
  • Backend architecture components
  • Real-time use cases from previous experience

👨‍💼 Hiring Manager (HM) Round

• Questions focused on:
  • Backend projects
  • Experience working at Juspay
  • Practical application of backend concepts

✅ Selected for the role

📝 Note: Giving interviews after 3 years was challenging but highly rewarding.

🔹 3. PayU – Frontend SDE / SDE-2 (Selected)

✅ Key Questions from Round 3:

1. Frontend App with Polling Strategy

   • Scenario: Initiate a transaction → Bank confirms asynchronously
   • Solution: Used polling mechanism (no code required; conceptual discussion)

2. React App Performance Optimization

   • Strategies for faster initial loads and build optimizations

3. Cache Invalidation After New Deployments

   • Ensuring users see the latest version post-deploy (e.g., service workers, versioning)

4. CORS Error Handling

   • Explained CORS, fixes, and IP whitelisting

5. JWT Token Handling

   • How to store, clean, and implement protected routes

6. Cookies vs Sessions vs Local Storage

   • Use-cases, lifetimes, and security considerations

7. Token/Payload Encryption

   • Preventing interception by API/network attackers

8. Authentication vs Authorization

   • Differences with practical frontend examples

✅ Successfully cracked the Frontend SDE/SDE-2 role