Referral-sourced 1.5 YOE hire: DB engine project deep dive+SQL+Binary Search on Answer, then graphs/thread safety, then culture fit

Background
Education: BTech CSE, 2022, Tier - 3 college, India
Experience: 1.5 Years of Experience in Product Based Company, India

Opportunity details
Date: Feb, 2024
Location: Gurugram, India
Role: SDE-1
Applied: Applied via Referral 4 months prior

Interview Process
Phone call:

• Got a call and email from recruiter, scheduled the interview in upcoming week.

Round - 1:

• Technical Interview (1 hour, got stretched to 1.5 hours)
• 5 mins, started with basic intro.
• 15 mins discussion about my current work in the company and details about what I do, and technologies I work on.
• 20-25 mins, project discussion. My project was a basic database engine like SQLite. Discussed about how databases work, how indexing work, B-Trees and everything I did in my project.
• 10-15 mins, writing one SQL query. The interviewer gave me 4-5 tables, and asked me to write an optimized SQL query. I wrote one using sub-queries, but that was not the most optimal way. He also asked me about difference between subqueries and joins, and which should be preferred when.
• 20-25 mins, coding question. I used Binary Search on Answer to solve the question. I had to write the complete working code, and then explain it.
• In total, the interview went 8.5 - 9 / 10, according to me.

Round - 2:

• Technical interview (1 hours and 15 mins)
• 15 mins discussion on prior experience. The interviewer asked me about REST APIs and other stuff written in my resume.
• 20 mins project discussion. I explained my project, which basically uses certain graph algorithms and implements a research paper. The interviewer asked how can we make this program thread safe. I told them, that we can use some locking mechanism, but I couldn't provide a good answer. Then they asked about internal implementation of a hash-map, which was being used in my project. I confused hash-maps with ordered-maps in C++.
• 30-35 mins coding question. Since we were discussing about graphs, I gave a graph based solution. But it was extremely un-optimal. It was an observation based question. Then they explained it and asked to write the code. They then gave a variation on the question, which I also solved.
• In total, the interview went 7.5 / 10, in my opinion.

2 days later I received an email that I've cleared the technical round, and asked me to schedule last round.

Culture-fit round:

• Went for about 30-35 mins with the VP of tech.
• They explained me about the work and work culture at Zomato, and why I should and shouldn't join Zomato.
• They also verbally offered me my offer and also told what my compensation would be.

Result
I got the offer and also accepted it.

Tips

1. Zomato hires only through referrals, and they might give you a call quite a lot of time after you have applied.
2. Try to convey your strengths to the interviewer (DSA, projects, prior experience).
3. DSA problems asked are not hard. They are mostly medium level questions that require some kind of observation.
4. Revising SQL, DBMS and OS is a good idea.
5. Prepare your resume well.
6. Be calm and try to listen to what the interviewer is saying.

Good Luck and All the Best!!