SDE - 1

Design a key-value store database. Here I need to design a map-like data structure without using any external libraries. 
There was a follow-up that what if keys can range from 0 to 10^12, but the space availability is only in the 10^6 range. here using BST or heaps you can come to a solution.

Design the *tail* command in linux. So Linux has a tail command which can be used to see last n lines (default 5) from a file. I needed to design this using other OS libraries. I was required to check for any space or new line issues. I was allowed to solve this in C or python using file reader. Here major constraint was that I was not allowed to read the whole file but only last n lines due to speed constraint.

I was asked to design a parallel sort algorithm, In this case I had 10 cores of CPU. However as a followup I did not have much RAM to read the whole data. So I was required to read in batches and use multithreading as well.