Paytm Interview Experience for SDE-1 | 2 Year of Experience

Round 1:

  1. Given a string of 1’s and 0’s

    • Score is calculated as {1’s in left part + 0’s in right part}
    • Compute the largest Score. 
    • Desired Solution complexity: Linear
  2. Given an N,

    • Generate all String of length N consisting of 0’s and 1’s
    • Such that no consecutive 1’s occur in resultant String.
  3. How does GC work in Java?

  4. Which DS would you use to create your own GC and Why?

  5. How does Optional work in Java?

Round 2:

  1. Find the median of an Infinite stream of Integers. He took 4 solutions to this question.

    • Sol1: Sort the entire inputs.
    • Sol2: Use insertion Logic for incoming elements.
    • Sol3: Using BST
    • Sol4: Using Heaps
  2. Give HLD for creating a REST API for POST and GET calls for a file using 3 cloud clients (Azure, s3, Google Cloud).

  3. Spring advisers and exception handling mechanism in Spring boot

Round 3:

  1. Given N, complete the isPowerOf2 function.
  2. In a series of buildings, Calculate how much water will be clogged.
  3. Explain Single level and multi-level indexing in DB.
  4. HLD for twitter.
  5. Which is better: Recursion or Iteration and Why?
  6. Why is String immutable in Java and does String immutability effects HashMap
  7. Which is faster ArrayList or LinkedList and Why?

Verdict: Selected.

Write your Interview Experience or mail it to

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.