Blogs By Jai-D

Carl Zeiss Interview Experience - FullStack Developer

January 01, 2021

Carl Zeiss came to IIIT Naya Raipur with 3 positions

  • FullStack Developer
  • Machine Learning
  • Python/C++

Eligibility criteria: 80%+ in 10th and 12th with 7+ CGPA in B.Tech.

I applied for the FullStack role as this is my strong point though I was tempted to go for Python/C++ because I love python but didn’t because I don’t know C about C++ and felt like I would grow more in the FullStack role.

Since the company came in mid-late November only 19 people in total applied and they all were asked to give the First Round.

First Round - Aptitude Test

It consisted of around 40-45 questions to be solved in 45 Minutes on the Pariksha Platform. You might need some practice beforehand to increase your speed. Almost everyone cleared this round and we were asked to attend the Placement Talk followed by a Technical Test.

Second Round - Placement Talk + Technical Test (Coding + MCQs)

We were told almost everything one could ask to know about the company, they showed the various fields the company works and various achievements of the company like

  • Images were taken on the moon during Apollo 11 mission used lenses made by Carl Zeiss.
  • Developing lens to be used by researchers and doctors to do very critical work in their fields
  • Working on Silicon Technology with companies like Apple
  • …etc, etc

We were supposed to start the test within 30 minutes after the Placement talk ended. It was conducted on Hackerearch with no camera and no full-screen mode.

Two hours long, it contained 40 MCQ questions based on OS, DBMS, and position specific questions (FullStack and development for me) alongside 3 coding questions of 20, 20, and 50 marks each. Most of the MCQs could be answered in 10-15 seconds if you knew the facts, there wasn’t much heavy calculation to be done. Even after having 90 minutes for 3 coding questions, I was only able to partially solve the 2nd one and but completed the 3rd one fully because it was a standard question which I had solved previously. The other two of 20 points were a bit more mathematical (my weakness :p) hence they ended up eating up a lot of my time with just a partial solution.

Luckily the situation was the same with everyone else which is why I was able to move into the next round. A total of 16 people out of 19 were selected for the next round (Quite a good amount).

Third Round: Technical Interview

The technical Interview was taken by two members (say A and B, A was junior to B), though most of the questions were asked by the A and B was just there probably analyzing my answers and behavior.
They outright asked me what things I know so I told them JavaScript, Node, and Python (+ Django). They asked me one simple coding question, if you are close or above to 1700 in CodeChef then you don’t need to worry in this section. The part which had me sweating is when they started asking a specific question regarding JavaScript like

  • How does JS support asynchronous nature being a single-threaded language
  • Difference between == and ===
  • How JS stores data and datatypes
  • and more which I can’t remember :p

I was able to answer most questions with confidence and ended the interview by asking some questions from my side about the workstyle, technologies used, and how work from home is affecting them

Fourth Round: HR Interview

It was supposed to happen at least an hour after my third interview ended so I left my laptop and phone to take a stroll and coming back after 15 minutes I see 3 missed calls and a message from HR to call him back. So I did and he asked if we could do the HR round in 5 minutes and we jumped on to a video call.

It was mostly just a confirmation call that yes you have been selected and some random question here and there about my family and how many brothers and sisters I have. After which it was mostly me asking questions and discussing how the internship will take place, their views on PPO opportunity and If we will be given any task or things to learn before the joining date (& more similar questions).

Just a tip

One thing I can recommend after this is that make sure to ask as many questions related to work-life and how the whole internship will take place or even ask about them about what they do (make sure to ask this in the tone) because everyone loves to talk about themselves whoever it might be. Asking a lot of questions even though you might know the answers reduces unknown variables and will make the recruiters confident in deciding to hire you.


In the end, 6 people got to the HR round and 5 were selected for a 6-month internship opportunity.

  • FullStack: 2
  • Machine Learning: 2
  • Python/C++: 1


I am hoping to document my internship in form of blogs every 1-2 week describing the kind of work I did and the new things I am learning because I as a fresher I was always interested in knowing what kind of work people did and how they approach problem working in a company. Hence I am starting a newsletter so that people can follow my journey and if it even helps even one person, it will be worth all the work. Consider subscribing to my newsletter and I’ll try to share any new blogs that I end up writing too.

Written by Jai Kumar Dewani who is still figuring out and developing his interest in development :p. Pretty active on twitter, follow me at @jai_dewani