Round 1:

https://leetcode.com/problems/linked-list-cycle/
Questions around what happens when you go to a website e.g. Google (DNS, TCP/IP etc..)
Difference between asymmetric and symmetric encryption

Round 2:

https://leetcode.com/problems/shortest-word-distance/
E.g. a,b,c,d,e,a
Word1 = a, Word2 = c
a->c = 1
c->a = 2

How would you test?