Ather

Role: Software Development Engineer (SDE)

College: Not Specified

Interview Date: January 2025

Interview Type: Full-Time

Result: Selected

Difficulty: Medium (not overly hard but mentally stimulating)

Rounds: 4 rounds

Topics Asked: Array Manipulation, Binary Trees, String Manipulation, Microservices Architecture, System Design (Ride-sharing system, Notification system), Data Storage, Caching, Scalability, Database Choices (NoSQL), Cross-Site Scripting (XSS), Behavioral Questions

Experience:

This interview experience for a Software Development Engineer (SDE) position at Ather Energy took place in January 2025. The process was engaging, balancing technical depth and practical problem-solving.

Round 1: Online Coding Test

This round consisted of two coding questions of medium difficulty.

• Question 1: Rearranging an array such that all even numbers are on one side and all odd numbers on the other, including edge cases like negative numbers and zeros.
• Question 2: Binary tree traversal problem to print the level order traversal in a zigzag pattern, using a queue and reversing output for alternating levels. The candidate passed all test cases.

Round 2: Technical Interview 1

This round combined coding and basic system design. The interviewer started by asking about the candidate's projects, particularly a machine learning model.

• Coding Problem: String manipulation, specifically removing adjacent duplicates until no more could be removed. The interviewer also asked for optimizations.
• System Design: Basic questions about designing a notification system, focusing on real-time updates, scaling, and user preferences.

Round 3: Technical Interview 2 (System Design Focus)

This round was a "mental marathon" focused on designing scalable and efficient systems.

• Design Task: Design a ride-sharing system for electric scooters, similar to Uber. The discussion covered microservices architecture (for users, rides, payments), data storage for live scooter locations, caching mechanisms for frequently accessed data, and scalability concerns (live tracking, dynamic pricing). The candidate also discussed handling scooter maintenance, downtimes, or cancellations, and database choices (leaning towards NoSQL for real-time location data).
• The interviewer challenged the candidate on potential bottlenecks in caching strategy, which the candidate addressed by adjusting the design to include distributed cache systems.

Round 4: HR Interview

This round included behavioral questions and a tricky question about balancing multiple priorities. The conversation flowed well, and the candidate answered based on real experiences.

Final Thoughts: The process was intense but rewarding. The candidate emphasized staying calm during system design rounds and being open to creative problem-solving. Recommended revisiting data structures and scalability principles.