Payu Interviews

🔹 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

I recently interviewed at PayU for an SSE role in Bangalore. I have 2.9 years of experience as an SDE1 at a product-based MNC.

The interview consisted of one problem-solving/data structures round. It started with introductions and a discussion about my projects.

Then, the interviewer presented two DSA questions. For the first question, I initially proposed an O(n^3) solution and then optimized it to O(n). I discussed the approach, and the interviewer asked me to code it on Google Docs. After completing the code, we dry ran it on a few test cases. The interviewer pointed out that my implementation was incorrect because it didn't explicitly maintain i, j, k. I tried to explain that the problem only required a boolean return value, but he disagreed. With 15 minutes left, he moved on to the next question without letting me finish discussing the first one.

For the second question, I solved it optimally using a sliding window approach on the first attempt. The interviewer asked for the time and space complexity. I explained that it was O(n), but he insisted it should be O(n^2) because of the use of two loops. Despite my efforts to clarify that the worst-case scenario involves iterating over the entire array twice, he didn't understand and abruptly ended the interview.

I honestly hope I don't get selected for this role.

I went through a two-round interview process for the SDE [Backend Java] position at PayU. The first round was focused on Data Structures and Algorithms, where I tackled questions involving array manipulation and flattening a nested list. The second round delved into technical discussion, presenting challenges such as finding the next greater number with the same digits and a detailed system design problem for a loan assessment job scheduler. I engaged actively, providing my best answers and addressing all follow-up questions on scalability, query optimization, data structure, and latency during the system design discussion.

I decided to share my interview experience with PayU since I couldn't find many resources online about their process. A recruiter from Naukri reached out to me, and after discussing my work experience and salary expectations, I was scheduled for an interview for a Senior Software Engineer position in Gurgaon.

1. Round 1: Programming

This round was conducted on the Intervue platform, where I had to write and execute complete code along with test cases. I was given two problems:

• One similar to Meeting Rooms III
• And another, Subdomain Visit Count

I managed to solve both of them successfully.

2. Round 2: Problem Solving, Fundamentals

Within two days, the recruiter contacted me to schedule the second round. This round focused on both programming and fundamental concepts.

Programming:

I was asked a problem similar to Binary Tree Right Side View.

Fundamentals:

The discussion covered several core computer science topics:

• What happens when you type www.google.com (or any site) into a browser?
• SOLID principles
• Memory Leak concepts
• Multithreading
• Java StringBuilder and related concepts

I felt confident about my performance in this round.

3. Round 3: Hiring Manager (Initial Attempt)

Again, the recruiter got back to me within two days to set up the next round. Unfortunately, this is where things started to go downhill. The interviewer didn't join on time, and after contacting my recruiter, he eventually joined from his phone while driving. I offered to reschedule, but he insisted on continuing. He didn't ask any technical questions, which I found surprising as I was expecting LLD/HLD discussions. Instead, he started asking what I considered irrelevant questions. Feeling that my time was being wasted, I directly asked if he had any design-level questions, to which he simply replied, "not needed." The interview concluded with a very unprofessional statement: "not everyone can go to IIT, so people go for some tier 3 colleges, maybe you should also follow the same!" Despite his arrogance and lack of professionalism, I ended the conversation with a smile.

Later, I received feedback from the recruiter stating that I was rejected because I "couldn't come up with a Database schema." This was clearly a random excuse, as our discussion never even touched upon technical subjects like database design. I decided to escalate this to HR, who then scheduled another Hiring Manager round with a different interviewer.

4. Round 3(II): Hiring Manager (Second Attempt)

This second attempt at the Hiring Manager round was a much better experience. We had a good discussion, and I was asked a couple of questions related to HLD fundamentals. Towards the end, there was also a DSA question similar to Container With Most Water. Overall, I felt very confident after this round.

I was expecting to hear back, but nothing happened. When I called the recruiter, he informed me that I had cleared all the rounds and asked for my documents (salary slips, etc.). Following this, I received an invite for an HR round, but once again, the HR didn't join. Upon calling the recruiter, he mentioned it was his last working day and he had left early. I asked for a reschedule, but it never materialized. The recruiter subsequently started ignoring my calls and emails. Given the numerous red flags, I decided to stop pursuing the opportunity.

Overall Experience:

My overall experience was pretty bad. It felt like I wasted almost a month clearing their interview process, only to be ghosted in the end. It's possible my salary expectations didn't align with their budget, but this was something I had shared upfront. I suspect they interview multiple candidates for one role and extend an offer to whoever accepts the lowest salary.