Java Intern Interview Experience

I recently cleared an interview for a Java Intern role in Pune. Due to privacy reasons, I won't be sharing the company name but I wanted to share the complete process because the rounds covered a good mix of debugging, Core Java, OOP, SQL, projects and basic DSA.

The internship is for 6 months with a stipend of ₹20,000 per month.

Round-by-Round Experience

Round 1: Debugging Round

My first round was quite different from a regular coding test.

I received six number-pattern programs with incorrect code. Instead of writing everything from scratch, I had to understand the expected output, locate the bugs and correct the existing code.

For me, this round was mainly about code reading, debugging and finding mistakes quickly.

Round 2: Core Java, OOP and SQL

In this round, I was tested on Core Java and OOP, with plenty of how-and-why follow-ups.

I discussed the four pillars of OOP, overloading vs overriding, abstract class vs interface, == vs equals(), exception handling and Java Collections.

For SQL, I had to write queries and then modify them when the requirements changed. I worked with joins, GROUP BY, aggregate functions and basic database concepts.

I also explained the projects mentioned on my resume and what I had personally contributed to them.

Round 3: Project Deep Dive and DSA

This was the most detailed technical discussion for me.

I explained one of my projects from end to end, including the technologies I used, why I chose them, the application flow and my database structure.

I also answered follow-ups about tables, primary and foreign keys, entity relationships and implementation choices.

After that, I received two coding tasks.

First, I had to implement a linked list from scratch, including node creation and traversal.

My second problem was Merge Sort. I explained the divide-and-conquer approach, recursive sorting and the merging process, along with its O(n log n) time complexity.

Round 4: HR Discussion

My final round was more conversational, talked about my background, communication, career plans and why I wanted to start my career in Java/backend development.

I also answered questions about how I learn new things, work with others and what I expected from the internship.

Interview Result

Selected for the Java Intern role in Pune. I received a 6-month internship with a stipend of ₹20,000 per month.

For me, the biggest learning from this process was that I couldn't rely only on DSA preparation. I also needed to be comfortable debugging existing code, explaining Java concepts clearly, adapting SQL queries and defending the decisions I made in my projects.

Preparation Tips

Based on my experience, I would focus on Core Java, OOP and SQL fundamentals first. I would also practise debugging existing programs, revise basic DSA implementations and make sure I could explain every important part of my projects without depending on memorized answers.