Doordash

Coding (Tech Phone Screen)

1. Given cities, x, y cordinates of the cities, query. Find the closest city. If the x,y cordinate of the city matches, then return None. Else return the city closest to the city in the query. If two cities are equidistant, compare the length of the name of the city. If the length is same, return the city which occurs first lexographically.

I/P : c = ["aa", "bbb", "ccc"]
x = [1, 1, 2]
y = [1, 3, 4]
q = ["aa"]
O/P: ["bbb"]

On Site

1. Coding round - Dashers with profit. Return Max profit. DP https://leetcode.com/discuss/interview-question/1320711/doordash-phone-screen
2. Behaviourial
3. Coding Round - Dasher chef. You are given skills, difficulty, profit for dashers. Return the most Profit that the kitchen can be produce.
   I/P:
   skills [2,3,4]
   difficulty [1,2,3,4,5,6]
   profits [1,2,3,7,9,8]
   Max PRofit : 2 + 3 + 7 (For skill 2, you can create a dish (1) with profit (1) or dish (2) with profit (2) Choose the max profit)
4. System Design - Create a system that can return the average rating of a restaurant for the past 30 mins. The list refreshes after every 5 mins

I honestly felt that the system design interviewer wanted me to fail. Whatever answer I gave him, he was like "That wont work". In the end he wanted me to store all the reviews in Kafka. I am still not sure how will that work. Can someone help me understand?