Groww

Role: SDE-1 Backend

College: BTech in IT from Tier-2 College

Interview Date: December 2024

Interview Type: Full-Time

Result: Accepted (Offer)

Difficulty: Hard

Rounds: 5 rounds (3 Technical, 1 Hiring Manager, 1 HR)

Topics Asked: Data Structures (Linked List), Algorithms (Dynamic Programming, Sliding Window, Two Heap), Low-Level Design (Group Chat), High-Level Design (Rate Limiter), Behavioral questions.

Experience:

The candidate received a call from a recruiter about 2-3 months after applying. The interview process consisted of 5 elimination rounds.

Round 1 (Coding - 60 minutes, with an SDE-1) involved three LeetCode-style questions: "Remove Duplicates from Linked List - II", "Number of ways to decode string" (DP problem), and a "Sliding window problem, longest substring having k max distinct characters." The interviewer was satisfied with the solutions.

Round 2 (Low-Level Design - 90 minutes, with an SDE-2) required implementing a "Group chat functionality" where an admin can create a maximum of 5 groups and a user can join a maximum of 20 groups, with admin capabilities to add/remove users. The candidate successfully completed the executable code and discussed the design and approach.

Round 3 (High-Level Design - 60 minutes, with an SDE-3) focused on designing a "Flickr Image Service rate limiter" for users with different subscription types. For example, a premium user could download 100 images per minute, while a general user could download 10 images per minute, with the requirement that an 11th request from a general user in the first minute should be processed after the minute ends, not rejected. The candidate, with the interviewer's help, achieved a satisfactory design.

Round 4 (Hiring Manager - 60 minutes) involved a coding question, a variation of the "Two Heap problem," stemming from a stock market scenario. The candidate discussed multiple approaches before coding in the last 15 minutes. Behavioral questions, including "why leaving the current organization before 6 months," were also asked.

Round 5 (HR - 60 minutes) consisted of standard HR questions. The final verdict was an offer.