Experience: 5+ years in Product based company.

Round-1 DSA
question is similar to this,
https://leetcode.com/problems/combination-sum/description/
Solved it with backtracking interviewer was okay with that.

Round-2 HLD
Design Hotel Reservation Bakend
I wasn't prepared for that question fully.
I have explained how i will store hotels and room data. I suggested to store data in elastic search because of faster search operations with different kinds of filters.

then interviwer asked me how will you manage inventory of rooms on each date. Here I suggested to use elastic search again with keys are like Date + location.

I think this is a mistake. because handling cunsurrency while booking will be complicated here. also i didn't mentioned different room types.

Interviwer is fully focused on managing inventory
this is discused in the book System design Interview an insiders guide volune-2 by alex xu. please read it.

Verdict - Rejected