It all happened in August 2025.

Recruiter contacted via mail and then she did a video conference to explain about the profile and about my experience. I was told it will be mostly backend work with a bit of frontend.

Pre-screening Round

• exceptions, errors
• create immutable class
• deadlock
• All solid principles with example
• factory, abstract factory
• encapsulation vs abstraction
• actuator, dispatcher servlet => both of which I didnt know.
• And the about my project => I explained I dont have much professional experince is Java and my current job is on C++. But I know java quite well and use it for DSA.
• I was expecting I would not be selected further due to my background and I couldnt answer the spring boot questions.

(about 10 days later i received call for Loop Rounds)

Loop Round 1 - Hiring Manager Round

• about myself
• current role
• She said they were looking for a frontend developer, but i mentioned recruiter had informed it will be mostly backend work. She was pretty surprised by it. Still the interview continued.
• asked a bit about api query params path variable request body
• System design question for bookmyshow kind of service
• was mostly interested in requiremnets and api design
• She wanted API request type, request body, response body all.
• She asked to skip db schema, estimations as time was less
• at the end asked to create the hld diagram
• The interviewer was friendly

Loop Round 2 - DSA

• He explained about the project and some interaction happend and asked the question for converting number to roman numeral.
• I gave a solution using Separate Mapping for all 1000,900,500,400 etc.
• Then he asked to keep only mapping of 1000,500 etc and not the combinations.
• So I just gave a solution with hardcoding the value, and he was not satisfied with it. He wanted it to be "Extensible"
• I could not come up with it.
• Then he said, for 1000 the next is at index +2 and so on
• and for 500, the next is at index +1 and so on.
• I coded the solution for it
• But I argued with him, you cannot call it extensible as there is no defined rule the for even indexes the subtraction one will be at +2, and for odd it will b at +1. Tomorrow I can say 950 will have its separate pattern.
• My point being if he wanted an "extensible" solution, he should not have started with roman numerals as they are fixed and no one is extending them, and his approach cannot be called fully extensible either.
• I didnt think of it much as I anyway had given a correct solution (although not extensible).
• The interviewer was very friendly

Loop Round 3 - Bartender Round

• He explained about himself
• Asked about my current work and current project.
• Asked about any feature I implemented.
• He tried to go pretty deep into the feature which In my opinion was not required as its not the agenda of this round.
• And my work was on C++ development of a specified protocol, he could barely understand it.
• I had prepared analogies for it so I can explain better, but he tried to go deep and deep, so I doubt he understood
• Question on disagreement with seniors.
• Interviewer was normal (neither friendly nor rude)

Loop Round 4 - DSA

• creates 2 threads
• create kind of producer and consumer to count odd and even numbers one by one (wait/notify was used)
• cloneable, serializable, transient
• Implement immutable class, use of final keyword in different places
• create singleton class with thread safetly
• Question : find cycle in linked list
• I gave slow/fast pointer and HashSet apporoach => He wanted another approach as well but anything else didnt come to my mind.
• Question : sum of value of all leaf nodes in binary tree
• => I implemented it but then he clarified he asked for sum of the deepest level only so I modified the solution within a minute.
• I gave recursive solution for both and did dry run
• Interviewer was normal (he appeared rude sometimes, but that just might be the way he talks!)
• This interview went very well and I was able to answer 90% of the stuff correctly.
• Couldnt answer some questions like drawback of Cloning, multiton pattern

Verdict : Not selected

Feedback from recruiter

1. The hiring manager told I failed to implement the DB schema (I mean, what the hell?). She never asked for the DB schema, she made me spend all the time on API design.
2. And she said I couldnt make the system design either => this I dont agree with her either as I did make the design, she asked no clarifying questions on my design and didnt give any input. So I had to give her options myself and tell her why I am choosing one of them. On 2 occasions I asked her should I go with this or that, and she replied "yes".
3. Another feedback was i couldnt comeup with a solution for the 1 DSA round, which is ofcourse not true. I agree i didnt spot the +1/+2 pattern but if he wanted an "extensible" solution he should have come up with a better question. Or atleast provided examples extending the bounds from roman numerals so it makes sense to use the pattern.

Conclusion
So, to sum up, stay alert from "friendly" interviewers.

And, I think most likely reason for my rejection would have been my c++ background or confusion regarding me not being a frontend developer. So the hiring manager cooked some stuff up. This in my opinion would just lower the morale of someone looking for a job.