Round 1: The online test

We had a two-hour window to complete the test, with 45 minutes allocated for the actual test. The test was divided into two parts: the first part consisted of multiple-choice questions (MCQs), and the second part was a coding test. The MCQ round included 30 questions covering various topics such as

Python
C++
Java
SQL
MongoDB
Database queries
OOP
Computer networks and security

The second part of the test was the coding section, which had 2 questions of easy to medium difficulty level

Round 2: The interview round

It was online through Microsoft Teams, which lasted for approximately 30 minutes. My interviewer had a significant background in IT and possessed expertise in software project management. The interview began with a brief introduction about myself, followed by technical questions. Here are the questions I was asked:

Explain various data types along with examples.
Discuss various data structures and their applications.
Share my preferred programming languages (for which I chose Python) and then code on a notepad. I was asked to calculate the number of occurrences of a word in a paragraph (ignoring letter case) and modify the code to count the occurrences of each letter.
Implement any pillar of OOP in any language I felt comfortable with (I opted for C++ this time).
Answer two SQL queries, one of medium difficulty and another slightly tricky.

Elaborate on the pillars of OOP with real life examples.