37 questions · from 3 interviews
Ola interview questions
Every question candidates reported from their Ola interviews, most frequently asked first. Each links to the write-up it came from, so you can see the round and how it went.
Ola coding and DSA questions
- 01
Shuffle Songs Without Repetition
Given a list of songs, how would you play them randomly (shuffle) such that no song repeats? Follow up: Can you do this in constant space?
Medium · From OLA | SDE 1 | Pune/Banglore
- 02
Consecutive Numbers Summing to N
Find the set of consecutive numbers summing up to n . For example, if n = 9 , output [2,3,4] and [4,5] .
Medium · From OLA | SDE 1 | Pune/Banglore
- 03
Area Under Histogram Variation
A question based on the famous 'Largest Rectangle in Histogram' problem with a slight variation.
Hard · From OLA | SDE 1 | Pune/Banglore
- 04
DNF Sort Variation
A problem that was a variation of the Dutch National Flag (DNF) sort. I was asked to explain why 3 pointers are used and the underlying idea behind DNF sort.
Medium · From OLA | SDE 1 | Pune/Banglore
- 05
Sort Array by Reversing Single Subarray
Given an array, determine if it can be sorted by reversing exactly one subarray. For example, in [1, 2, 3, 4, 8, 7, 6, 9] , reversing the subarray from index 4 to 6 results in a sorted array.
- 06
Two Sum (Specific Target)
Find pairs of numbers in the array [1, 2, 3, 4, 8, 7, 6, 0] that sum up to 6 (X). Assume positive numbers and distinct elements. Expected output example: [[2,4], [6,0]] .
Easy · From Ola | SDE2 | Feb 2021 | Pune | Offer
Ola system design questions
- 01
Design Online Streaming Platform
I was asked to design an online streaming platform during the system design round.
From OLA || SDE 2 || WORST INTERVIEW EXPERIENCE || Aug 2022 [Rejected]
- 02
Design Movie Ticket Booking System
Design a movie ticket booking site/app similar to BookMyShow. The discussion was very high-level, focusing on my approach and follow-up questions, with no coding involved.
Hard · From OLA | SDE 1 | Pune/Banglore
- 03
Design BookMyShow Seat Booking System
Design a seat booking system similar to BookMyShow. Key requirements included: GetSeatsInfo : Fetch seat information with grid details, screen, seat categories, seats layout, color coding for UI. Discuss storage in DB, request/response formats. BookSeats(User…
Hard · From Ola | SDE2 | Feb 2021 | Pune | Offer
- 04
Rebuilding Project with New Tech Stack
If you had to recreate this project from scratch, what new tech stack would you choose and what would be your approach? Justify your choices. (My answer involved Microservices)
- 05
Justification for Microservices
Explain your reasons for choosing a microservices architecture.
- 06
Microservices in Current Project
Identify and describe the potential microservices within your current project.
- 07
Tech Stack for Each Microservice
Specify the tech stack for each microservice identified in your current project.
- 08
NoSQL to Relational DB Migration Rationale
Discuss problems encountered with NoSQL databases that would lead you to consider switching to a relational database.
- 09
Designing Data Pipeline for Analytics (without Relational DB)
Given a project requiring analytics, and a constraint against using relational databases for analytics queries, how would you approach the database design? If a data pipeline is proposed, how would you design and implement it?
Hard · From Ola | SDE2 | Feb 2021 | Pune | Offer
- 10
RabbitMQ vs. Kafka and Message Queue Internals
Explain what RabbitMQ is. Discuss the differences between RabbitMQ and Kafka. Describe the core components of a message queue system.
- 11
Need for Message Queues and Use Cases
Explain the necessity of message queues and provide scenarios where you have used them in your current project.
- 12
Redis: Capabilities and Message Queue Use
Explain what Redis is. Can Redis be utilized as a message queue?
- 13
Caching Fundamentals
Define caching and explain how it contributes to system performance.
- 14
Internal Workings and Design of Monitoring Tools (Kibana/Grafana)
Explain the internal mechanisms of tools like Kibana and Grafana. If tasked with designing a similar monitoring system, how would you approach it?
Hard · From Ola | SDE2 | Feb 2021 | Pune | Offer
- 15
Database Choices for Monitoring Tools
What type of database would you choose for implementing systems like Kibana and Grafana, and why?
- 16
Cassandra for Write-Intensive Monitoring Systems
Discuss the suitability of Cassandra for monitoring systems, particularly its advantages in scenarios with extensive write operations.
- 17
Integration and Log Ingestion for Monitoring Tools
Explain how logging tools are integrated into an environment, how they acquire container-specific details, and the process by which log messages are pushed to systems like Kibana.
- 18
Load Balancing: Concept and Necessity
Define load balancing and explain its importance in distributed systems.
- 19
Proxy vs. Reverse Proxy
Distinguish between a proxy and a reverse proxy.
- 20
Apache ZooKeeper Mechanics
Explain the internal workings and principles of Apache ZooKeeper.
- 21
Sharding: Definition, Need, and Rationale
Define database sharding, explain when it is necessary, and justify its use.
Ola behavioural and HR questions
- 01
Most Challenging Project
Discuss the most challenging project you've worked on, detailing the specific challenges and how you overcame them.
- 02
Flaws in Current Project
Discuss the flaws or shortcomings present in your current project.
- 03
Conflict Resolution with Manager/Peers
Describe any conflicts you've experienced with team managers or peers and how you effectively resolved them.
- 04
Best Manager Feedback
Share the most positive feedback you've received from a manager during a performance review.
- 05
Handling Critical Manager Feedback
Describe any constructive or critical feedback you've received from a manager and how you addressed it.
- 06
- 07
Candidate Questions for Interviewer
Do you have any questions for us?
Ola other questions
- 01
Project Tech Stack
What tech stack did you use in your most challenging project?
- 02
Rationale for Tech Stack Choice
Explain the rationale behind choosing the specific tech stack for your project.
- 03
Application Monitoring Tools Experience
Discuss your experience with application monitoring tools like Kibana and Grafana.
Ola interview questions FAQ
What questions are asked in Ola interviews?
Candidates reported 37 distinct questions across 3 Ola interviews. 6 coding and DSA questions, 21 system design questions, 7 behavioural and HR questions, 3 other questions.
How difficult are Ola interview questions?
Of the questions candidates rated, 11% were easy, 33% medium and 56% hard.