There was total 4 round in Paytm

First Round was online coding test,
Technical Interview-1
Technical Interview-2
HR Interview
In first Round there was 3 coding questions,
Binary Search
Graph
Priority Queue
In Second Round there was questions on:

1. Shortest Path Algorithms
2. OOPS concept
3. Multithreading questions
4. Merge Sort

In Third Round there was questions upon:
1: Design HashMap
2: Kedan's Algorithm
3: Some Java Questions like String vs String Buffer and Garbage Colletor.

In HR Round they asked me about my previous work experiance and some Questions related to my Final Year Project.