Kotak

Role: SDE 2 (Backend Engineer)

College: Not Specified

Interview Date: 2024

Interview Type: Full-Time

Result: Rejected

Difficulty: Not Specified

Rounds: 3 Rounds

Topics Asked: Data Structures, Algorithms, Low-Level Design, High-Level Design, System Design, Concurrency, Database, Deployment

Experience:

The candidate, previously at Google, interviewed for an SDE 2 Backend Engineer role at Kotak. The process involved three rounds.

Round 1 (Bar raiser round): This round was conducted by an external company. It included DSA questions like "Search in a rotated sorted list" and "Minimum sum subarray greater than K." For Low-Level Design (LLD), the candidate was asked to design class diagrams, APIs, entities, and design patterns for an order management system where users could perform CRUD operations on orders and view their cart. High-Level Design (HLD) questions covered how to handle concurrency in a database and deployment strategies to ensure system stability during production deployments. This round reportedly went great.

Round 2 (Coding): This was the first round with someone working at Kotak. It involved two coding questions: "Given a large number as a linked list, Add one to it and return" (expected iteratively, e.g., 1->9->9->9 becomes 2->0->0->0). The second question was "Given a parking lot with In and Out times of cars, Find the minimum size of the parking lot so that no car has to wait" (similar to Minimum Number of Platforms Required for a Railway/Bus Station). The candidate coded both solutions, and the interviewer was satisfied with the approach and time complexity.

Round 3 (Design): This round focused on designing an IRCTC train seat booking system. Key requirements included ensuring data consistency, designing APIs, and defining the database schema. A specific catch was presented: if a seat is booked from station 1 to 3 and then station 5 to 10, a user searching for seats between station 3 and 4 (or 5) should still be able to view this seat. The candidate found this interview challenging, noting that the interviewer frequently interrupted and seemed to have a specific approach in mind.

Despite a difficult third round, the candidate received an email confirming they were moving forward. However, after salary discussion, the recruiter did not follow up with an offer letter, leading to rejection after almost a month of waiting.