I applied for the Junior Data Engineer Intern position at BlueCopa via LinkedIn. After about a week, I received a shortlisting mail containing details about the position, location, and stipend.

The hiring process consisted of three rounds:

Resume Shortlisting

Online Assessment

Interview

Round 1: Online Assessment

Along with the shortlisting mail, I received an invite for the Online Assessment (OA), which had a duration of 1 hour 30 minutes.
I found this OA quite unique — it had around 6–8 modules comprising:

Python-related questions

SQL questions

Simple math and aptitude questions

English grammar

And some memory-based tasks (for example, a 3×3 block showing numbers that had to be memorized and later arranged in ascending and descending order).

I completed this round in about 70 minutes.

Round 2: Technical Interview

The next day, I received a mail stating that I had cleared the OA and was selected for the interview round. I scheduled my interview for 06-11-25, and to my surprise, the duration mentioned was only 30 minutes.

I reached out to a few current interns to get an idea of the interview process. They mentioned that the questions were mostly based on SQL, Python, and some basic coding problems like:

Fibonacci number

Reverse a linked list

Find the maximum and second maximum in an array

So, I felt confident that I could clear this round since it was supposed to last only 30 minutes.

Interview Experience

On the interview day, the interviewer began with his introduction and gave a brief overview of the company. After that, I introduced myself.

He started with OOPs concepts — asking about the four pillars of OOPs, the difference between overriding and overloading, abstract classes, interfaces, and the difference between them. I answered all of them with proper examples.

Then he moved on to SQL questions, which included:

GROUP BY

Different types of JOINs (in detail)

Difference between HAVING and WHERE

Indexing

Normalization

He also gave me a table and asked me to perform a few SQL operations on it.
By this time, more than 30 minutes had passed, and I was happy that I had answered everything well — assuming the interview was about to end.
However, the interview stretched to almost 2 hours 😅.

DSA Questions

He then moved to Data Structures and Algorithms, where he asked one easy and three medium-level problems:

Longest Consecutive Sequence

Reverse Words in a String

Valid Anagram

A variation of “Move Zeroes to End” (I couldn’t find the exact question on LeetCode, but it was slightly different from the standard one).

Project & Miscellaneous Questions

After that, he asked a few questions related to my projects.
By this time, I was mentally drained, and I couldn’t answer some questions properly. Also, I had mentioned in one of my projects that I “optimized it by 20%” and had “50+ active users” — which I had added just to improve my ATS score 😅. Unfortunately, that left a negative impression.

There were also a few Java-related questions, such as the difference between JDK and JRE, and one more OOPs-based question, which I couldn’t answer correctly.