Role: Software Development Engineer II (SDE 2)
College: Not Specified
Interview Date: August 2024
Interview Type: Full-Time
Result: Selected
Difficulty: Medium
Rounds: 4 rounds
Topics Asked: Data Structures, Algorithms, Low-Level Design, System Design, Authentication, Design Patterns, Project Discussion, Behavioral
Experience:
The candidate was reached out by a recruiter via Instahyre for an SDE 2 position. The interview process consisted of 4 rounds focusing on DSA and LLD.
Round 1: DSA
Two standard LeetCode questions were asked, with emphasis on time and space complexity.
- Best Time to Buy and Sell Stock II
- Rotting Oranges
The candidate solved both optimally and the interviewer was satisfied.
Round 2: LLD
This round included one LLD question, authentication concepts, and design patterns.
- Design a system for managing customer orders and deliveries in a quick commerce platform. This involved structuring the system for customer orders, inventory, and deliveries; designing for order prioritization (especially during peak times); and handling different payment methods (credit cards, digital wallets, cash on delivery). The candidate started with DB design, then discussed APIs for adding products to cart and placing orders, including edge cases and error handling.
- How authentication can be done in the above two APIs? Suggested JWT tokens and explained their working.
- What kind of design patterns can be used here? Suggested Factory Pattern, Builder Pattern, and Strategy Pattern for several features, with a deep dive into Factory Pattern for payments.
Round 3: HM (Hiring Manager)
This round covered one LLD question, one DSA question, previous project discussion, and behavioral questions.
- Design an app like Google Calendar. Users should be able to create meetings with title, description, start/end time, location, and participants. The system should send notifications, and users should be able to accept/decline invitations. The discussion focused on DB design, separating shared and personal calendars, and permissions. Coding was skipped.
- Insert new nodes into a Circular Linked List (CLL) in such a way that they always remain in sorted state. The candidate provided an O(N) optimal solution.
- Behavioral questions included "What was your favorite feature that you implemented in your previous orgs?" and "How do you handle conflicts in work and handle work pressure in tight deadlines?".
Round 4: HR
This round lasted for 20 minutes, primarily discussing the working culture at Zepto and answering candidate's questions.
Result: The candidate received an offer call the next day.