current company: Walmart Global Tech
yoe: 2.8

OA

2 leetcode easy-medium level questions

R1

projects discussion
given a string, return all subsequences except "" in sorted order
given images in a matrix of 0/1, do the following:
horizontally invert
vertically invert
rotate image to 90, 180 and 270 deg

R2

For a given string, return minimum substring that has all the characters present in string
given start and end time of meetings, return minimum number of meeting rooms required

R3

projects discussion
implementaion of image comparision in js

R4

first asked for backend related: to design library that sets up connection to db table. I requested the interviewer to ask me from frontend side since I dont have any experience in backend. Then he asked below one
system design for drag and droppable query builder system for hospital. where internal staff can come and build query for retrieving appointment information for patient for selected time in some particular dept. something like that.

I was able to solve all the questions (except backend one sd) and Im awaiting feedback. Gave all 4 interviews on 29th Mar.
Do you think they'll reject for not solving backend system design ques ???

Update: I got the offer, here are the details https://leetcode.com/discuss/compensation/5040417/Salesforce-MTS-Offer