21 questions · from 7 interviews
Juspay interview questions
Every question candidates reported from their Juspay interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Juspay coding and DSA questions
- 01
Dynamic Tree Queries for Shortest Path
A tree with weighted edges is provided. You must handle Q queries of two types: Update the weight of the edge between nodes x1 and x2 . Given two nodes x1 and x2 , compute the shortest distance between them. For each query of the second type, return the sum…
Medium · From JUSPAY ONLINE TEST EXPERIENCE ONCAMPUS ROUND1
- 02
Minimum of Peaks in Fixed‑Size Sliding Window
Given an array [a1, a2, ..., an] and a window size k , compute the minimum value among all peaks of each window. A peak is defined as the highest value within a window. Return this minimum value.
Easy · From JUSPAY ONLINE TEST EXPERIENCE ONCAMPUS ROUND1
- 03
Lock-Unlock Tree Upgrade System
Problem: Lock-Unlock Tree Upgrade system Focused on tree-based logic and state transitions
- 04
Rainwater Puddle Formation
Graphs (Disjoint Set Union problem): Rainwater Puddle Formation
- 05
Count Inversion Pairs
Count Inversion Pairs(brute & optimal via divide & conquer)
- 06
HashMap Internal Working and Time Complexity (Java)
The interviewer asked me how a HashMap works in O(1) time complexity. Since I use Java, I explained how HashMaps work both before and after Java 8.
Medium · From Juspay Interview Wrost Experience Oncampus sde backend intern 2025 #juspay #hackathon juspay
- 07
Design Thread-Safe Tree Locking System
Design a thread-safe locking system for a tree. Each node can be locked by a user only if: None of its ancestors or descendants are locked. Locking/Unlocking must be thread-safe (no race conditions). The solution should efficiently support concurrent…
Hard · From Juspay Tree of Space Hackathon Part B Thread Safe
- 08
Find the Person with the Highest Score
Given q queries where each query consists of a name and a score, we need to find the person with the highest cumulative score at the end of all queries. In case of a tie, the person who reached the highest score first should be the winner. Test Cases: Input…
- 09
Job Scheduling with Minimum Maximum Load
You are given an array of jobs where jobs[i] represents the time required to complete a job. Distribute these jobs among k workers such that the maximum time taken by any worker is minimized. Test Cases: Input 1: 3 3 2 3 3 Output 1: 3 Input 2: 5 1 2 4 7 8 2…
- 10
Implement Lock, Unlock, Upgrade on Tree
On a tree structure, implement Lock, Unlock, and Upgrade functions. The solution needs to be both efficient and logically sound.
- 11
Thread-Safe Tree Lock/Unlock/Upgrade
Improve the time complexity of the tree lock/unlock/upgrade solution from Part A and implement a thread-safe version without using external libraries or atomic variables.
- 12
Optimize Interpreted Code Runtime
I was asked to improve the runtime of the following interpreted language code, given the hint that the function call is redundant and can be cached to improve performance: cpp Function f(int c) { c++; print(c); return c; } main { int c=0; for(int i = 0; i <…
Juspay system design questions
- 01
System Design: Scaling a Feature
There was a system design question related to my project, specifically on how I would scale a particular feature.
From Juspay sde intern hiring(oncampus) process + experience
- 02
Thread-Safe Lock-Unlock Tree System
8-hour challenge to make Part-A's solution thread-safe. Implemented with and without mutex using granular locking. Used parallelism & threading for better performance.
- 03
Build a Spaceship from Earth Resources
The interviewer asked: 'If you're stuck on a planet like Earth, how would you build a spaceship using only Earth’s resources?'
From Juspay Interview Wrost Experience Oncampus sde backend intern 2025 #juspay #hackathon juspay
- 04
Build a Steam Engine from Components
The interviewer shared his screen and showed 8 components. He asked me to build a steam engine using them.
From Juspay Interview Wrost Experience Oncampus sde backend intern 2025 #juspay #hackathon juspay
- 05
Optimization and Thread Safety (Mutex/Semaphore)
Discussion on optimization and thread safety using mutex/semaphore and without them.
Medium · From Juspay Interview Wrost Experience Oncampus sde backend intern 2025 #juspay #hackathon juspay
- 06
YouTube Request Differentiation
How does YouTube differentiate between requests from: - Two tabs playing YouTube on the same laptop - Two different laptops on the same network - Two laptops connected to different Networks
- 07
Google Drive File Upload and Sharing
How are files uploaded to Google Drive and shared between two systems?
Juspay other questions
- 01
Optimize Code and Ensure Thread Safety
I was asked to explain my existing code (from Part A of the Hackathon), optimize its approach, derive the time complexity of the optimized code, and then make the code thread safe. This involved implementing everything from scratch.
Hard · From Juspay sde intern hiring(oncampus) process + experience
- 02
How a Toilet Flush Works
The interviewer asked: 'Do you know how a toilet flush works?'
From Juspay Interview Wrost Experience Oncampus sde backend intern 2025 #juspay #hackathon juspay
Juspay interview questions FAQ
What questions are asked in Juspay interviews?
Candidates reported 21 distinct questions across 7 Juspay interviews. 12 coding and DSA questions, 7 system design questions, 2 other questions.
How difficult are Juspay interview questions?
Of the questions candidates rated, 17% were easy, 50% medium and 33% hard.