I applied to OLA through referral for the position of SDE1.
Round 1 (F2F Virtual Interview): 4 DS Algo questions(codepair round on hackerrank).
Q1: Reverse an array.
Q2: Rain Water Trapping problem.
Q3: Minimum time needed to burn a tree starting from a node.
Q4: Minimum cost for joining ropes of different length.(Follow up:Implement your own heap).
Round 2(F2F Virtual Interview): 3 DS Algo questions(share screen and code) .
Q1: Generate all permutation of a string.
Q2: Generate all distinct permutations of a string.
Q3: Generate next smallest permutation of a number.
Round 3(F2F Virtual Interview): 2 DS Algo questions(share screen and code).
Q1:Given a n*m grid of different characters, check if a cycle of size greater than three exists.(cycle must contain similar characters, consider left right up bottom character as neighbour)
Q2:Product of Array Except Self(https://leetcode.com/problems/product-of-array-except-self/ 2).
Round 4(F2F Hiring Manager round):
Questions related to my project.
Questions on scaling(Vertical scaling vs horizontal scaling).
Questions on SQL vs NOSQL.
Types of HTTPs method.
Difference between PUT and POST.
How would you search all the numbers common in a small file and a big file.
What DS would you use while creating your own hashing algorithm.
Some behavioural questions.
For all DSA question they asked to explain the approach first and then code. In between lot of cross question was asked.
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course. In case you are prepared, test your skills using TCS, Wipro, Amazon and Microsoft Test Serieses.