[garfij]

What are some signs a résumé was created in LaTex?

[doix]

The font will be Computer Modern, that's the most obvious one.

[jakey_bakey]

Basically this; the advice could just as easily read "use Computer Modern font" but that wouldn't get as much controversy/engagement

[SantalBlush]

Everyone seems to be missing the main benefit of using LaTeX: it creates professional-looking documents. That is its whole purpose. I use Adobe Garamond Pro in my LaTeX résumé, and while I'm sure nobody recognizes that it's LaTeX, the document just looks sharp.

[ornornor]

Perfectly aligned paragraphs on the left and the right. Other packages produce ragged line ends and/or ridiculous spacing between words (Word’s justify)