The objective in an interview like this shouldn't be to grade the quality of the code you bring in any sort of scale, but to have a discussion about the options you took. In that sense, it really matters very little what you present as long as we can do a small back-and-forth that lets me into what sort of person you are.

> but to have a discussion about the options you took

I can clearly state that this is not I commonly think about code that I write privately (and also for code that I write for the job only if I must). For private code, I rather commonly start with a "gut feeling" about some unexpected symmetry that the problem that I am working on likely has, then try to formulate these "gut feelings" as mathematical properties, and later theorems. At the end, everything "fits (for outsiders: unexpectly) together".

Thus, there is hardly ever a "option that I took", but rather a "I let everything flow: from the source [my gut feeling] to the sea [which is - ironically - the source (code)]".