Difficulty Level: Medium
I had applied for Hashedin in October through their career page, my online test was scheduled for the last week of November.
STEP 1(Online Test): Online test was conducted on codility platform. There were 3 questions which are to be solved in 1.5 hours.
- 1st Question is a basic array and sorting implementation.
- 2nd Question in Medium 2d-DP question. ( Not a standard Question)
- 3rd Question is a Dp question again wherein you have to find a proper substring of a given substring which is both suffix and prefix.
- I have solved 1st question completely and the rest of them with 70 to 80 percent.
Note: You need to submit your code on basis of example test cases only once submitted cannot be changed, So take good care of all edge cases.
STEP 2(Technical Interview “1-hour”): I have been informed on the 1st of December that I have been shortlisted for interviews and it was scheduled for 2nd December. The interview started with introductions on both sides Followed by CS fundamental Questions. Some of the questions I remember were:
- Inheritance and its Types.
- 3-Layered Architecture of DBMS.
- Transaction Control Language.
- Function Of Data Link Layer.
- What is Dynamic Programming?
- In which Scenarios do we use Dynamic Programming.
After This I have shared a google doc with two coding Questions:
- Given a list of words you need to group all the sets of anagrams that exist in the list.
- Given a list of numbers find pairs such that the difference between two numbers is k.(Negative numbers were also present in the list)
(need to do in constant space and Time: O(nlogn).
You need to obtain output and be sure of all the time Complexities.
STEP 3(Technical Interview “1-hour 30-minutes”): On the same day of first technical interview at around 10pm I was informed that I have cleared the round and I will have my next interview after a week. My second round was scheduled on 8th of December. Began with friendly introductions and details into which programming language and tech stack I am comfortable etc. As my resume says I am more of a python programmer. Some questions were asked on it along with CS fundamentals.
- Garbage Collection in Python.
- Functional Programming and Higher Order Functions.
- Decorators
- Context Managers
- Multi-Threading in Python
- Singleton Objects
- Composition and Aggregation.
After These theory Questions we Moved onto DSA:(Google Doc again)
- Write a function to find nth Fibonacci Number in O(n) time and constant Space(No stack space also so rule out Recursion).
- Coin change Problem.
Note: Proper explanation of code is required with time complexities.
Design and SQL Questions:
- I was asked to design the schema for an Instagram kind of application that has only functionalities of followers, Following, posting pics, and viewing the feed.
- Make sure to project your ideas while writing the tables, Take care of foreign keys and redundancy.
After writing down the tables I was two SQL queries on them.
- Fetch recent photos of a user.
- Fetch the posts to be displayed for a user.(only whom he follows is the important part here).
The interviewer was very friendly and kept on suggesting better ways.
After two days I was informed I am shortlisted for the Hiring-Manager Interview:
STEP 4(HR Interview “30-minutes”):
- Education Background.
- Where do you live.
- Why Hashedin and what excites you to join Hashedin.
- Two puzzles were given after this.
On the evening of the same day, I was informed that I have been SELECTED.!
Being Confident is the Key..!!