Date/Time: Early Jan 2022

Knowledge based questions:

1. System Internals (Memory / CPU)
   a) Thread v/s Process. How does one thread communicates with other thread, and how does one process communicate with other process?
   b) What is garbage collection? What needs to be done if it is not handled by the programming language? Under which scenarios garbage collection does not work well?
   c) Stack v/s Heap in the context of memory allocation, variables etc.
   d) A couple of other questions / followups that I don't remember.
2. OOD
   a) Dependency Injection
   b) Inheritance v/s Composition
   c) One more question I don't recall (not polymorphism).

Coding Questions:

1. Given a string and an array of words, find the first word that can be created by using letters of the string. For eg. if string is "balloons" and words are ["son", "ball", "friends"] return "son" as it is the first word that can be constructed using letters from "balloons".
2. https://leetcode.com/problems/word-search/ but have to also return position of where the word was found in the matrix and need to go only in right and down directions in the matrix. Word is guaranteed to be in the matrix.
3. Multiple words are given for searching in the word search problem (2) but each letter in the matrix can only be used towards one word. Not completely sure if the objective was trying to match maximum words or returning the index of matching words (assuming all can be matched). Very few minutes were left for this so couldn't discuss much with the interviewer about this. I think I only provided some brute force solution but not sure if it was correct.

Solved first two coding questions and answered some of the knowledge based questions (don't think I answered very well on the system internals but did okay on the OOD) and heard next day from the recruiter to proceed for the onsite round.