WEX Software Engineer 2 interview questions

I could give only Two rounds First round was DSA -> it was a dp hard question where you have a string like 012012, count number of subsequences such that there is atleast one 0, one 1 and one 2, and it should be in that order i,e 0 then 1 then 2 2nd round was system design, expected a HLD round , turned out to be a LLD round