Ola Electric

Role: SDE-1

College: Not Specified

Interview Date: June 9, 2025

Interview Type: Full-Time

Result: Rejected

Difficulty: Medium-Hard

Rounds: 4 rounds

Topics Asked: Data Structures (Strings, Graphs), Algorithms (Sliding Window, DFS/BFS), System Design (URL Shortener, SOLID Principles), Puzzles, Behavioral.

Experience:

This candidate interviewed for an SDE-1 role and went through four rounds.

Round 1 (Problem-Solving - DSA-Based): The first question was string-based, requiring the sliding window technique. The second question was the classic "Number of Islands" problem. The interviewer also asked to modify the code to calculate the area of the largest island. The candidate solved both questions successfully.

Round 2 (System Design): This round focused on designing a URL shortener service like Bitly. The interviewer asked about the database schema, choosing between SQL/NoSQL, handling collisions, custom URLs, and cleaning up expired URLs. Finally, the interviewer asked how the design would change to track the number of times a short URL was accessed. The candidate addressed each point in detail, and the interviewer seemed satisfied.

Round 3 (Hiring Manager): This round began with introductions, followed by questions about the candidate's current role and work experience. Technical questions focused on SOLID principles, asking for explanations with code snippets. A puzzle was presented: "A census taker approaches a woman standing by house number 14 and asks about her children. She says, 'I have three children, and the product of their ages is 72. The sum of their ages is the number on this gate.' After doing some calculations, the census taker says he still doesn't have enough information." The candidate struggled to confidently pick one solution for the puzzle.

Result: The candidate had a gut feeling that things might not go in their favor after the puzzle round, and a few days later, the recruiter informed them that they were not selected.