I started by explaining the approach to serialization using preorder traversal of the binary tree, converting nodes into a string format with a delimiter. The interviewer engaged with my thought process, asking me to clarify how I would handle null nodes.

I elaborated on using a placeholder value for nulls, which seemed to resonate with them. After that, I moved on to deserialization, stressing the importance of backtracking through the string to reconstruct the tree.

Unfortunately, I stumbled on edge cases, specifically regarding trees with only one child on one side, which led to some confusion during my explanation.