Blinkit · Junior — 3 rounds, DSA + system design + culture fit, offer accepted

I applied through Instahire and the entire process took about a week from the recruiter callback.

Round 1 — DSA

Question 1: Frog Jumping Problem

Given n stones with frogs on some of them, a frog can jump to the next vacant stone (jumping over other frogs if needed). I needed to find the minimum number of jumps for all frogs to reach the rightmost stone.

I initially explained a greedy approach favoring jumping over as many frogs as possible. After some dry runs and discussion, I realized the solution was actually O(1)—finding the index of the leftmost frog. The interviewer was satisfied.

Question 2: Binary Search Tree Node Removal

I was asked to explain how to remove a node from a BST. I struggled to independently identify the leftmost node of the right subtree or rightmost node of the left subtree approaches and needed help from the interviewer.

Round 2 — System Design (75 mins)

I spoke with an SDE-2 who asked me to design a rider onboarding application.

• Requirements & Scope: First 15-20 minutes defining the problem space
• Database Choice: SQL vs NoSQL — I was thoroughly grilled on my decisions
• DynamoDB Deep Dive: Discussed internal details, index types, table design, and how to define Partition Keys and Sort Keys for each table
• Performance: Discussed ways to reduce HTTP server latency, including status code-based retries, long polling, and short polling

I received positive feedback from the interviewer.

Round 3 — Culture Fit

This was a brief alignment discussion on Blinkit's fast-paced work culture. I received the offer in this round and accepted without negotiation, as it exceeded my expectations.