The interview consisted of three face-to-face rounds:

• Machine coding round: Coding on your own laptop. The code should be runnable.
• Technical Interview: Data structures, algorithms, and questions on previous projects.
• Interview with CTO: Mostly on architecture and previous company details.

Machine coding was to design runnable code.

Problem Statement:

Given a customer's Geo Location (Lat-Long) and a List of Restaurants. Each restaurant consists of:

• Lat-Long of the restaurant

• Name

• List of Items, where each item has:

  • Item Name
  • Prep Time
  • Sensitivity (Low, Medium, High). Lower sensitive items like ice cream cannot be delivered more than 2 KM.

• Find the List of Restaurants given an empty customer cart.

• Find the SLA (Time to deliver) given a cart, restaurant, and customer.

• Parameters should be configurable like Sensitivity, Max prep time, etc.

Second Round:

• Given characters a-z, find the nth permutation. Where all permutations are only ascending. For example:

  Given characters a, b, c. Valid permutations are: a, b, c, aa, ab, ac, bb, bc, cc, aaa, aab, aac, abb, acc, baa, bab, bac, bbb, bbc, bcc, caa, cab, cac, cbb, cbc, ccc

  The 4th permutation is: aa

• Questions about the project.

Third Round with CTO:

Design Flipkart Flash sale architecture. Handle 2 million hits and 20k orders in 2 seconds. Find out database scalability.