I'm a founder/CEO rather than a formal CHRO, but at Dynaris I've held the people function for the first three years, which is functionally the same role with worse sleep. The skill that unexpectedly became crucial, and that I had no real foundation in, was reading first-week disengagement signals in writing samples, not in conversation.
I used to think the way to read whether a hire was going to work was through 1:1s and gut feel from meetings. That's the conventional CHRO toolkit and it's where most of the literature points. What I noticed over our first dozen hires was that the conversation signal was unreliable, especially with strong communicators, who can perform engagement without feeling it. The much more accurate signal turned out to be how someone wrote in their first two weeks. Specifically: the texture of their async updates, the questions they asked in PR comments or document threads, and whether their writing got looser and more opinionated over time or stayed careful and corporate.
People who are going to thrive at the company write more loosely and confidently as they get more comfortable. They start using internal jargon, making jokes, taking small contrarian positions in writing. People who are quietly checking out write the same way at week eight as they did at week one. Polite, correct, and without fingerprints.
I developed this by accident. After two early hires didn't work out despite great verbal interactions, I went back through their Slack and document history looking for what I'd missed. The pattern was visible weeks before the formal performance signal showed up. Now I read every new hire's first two weeks of writing as a deliberate calibration exercise, and I act on the signal much faster than I used to.
The broader skill, if I had to name it, is text-as-data for personnel decisions. It feels uncomfortable at first because it sounds surveillance-adjacent, but in practice it's no different from a manager noticing body language, just done in the medium where most distributed work actually happens. For any people leader of a remote or hybrid team, it's the highest-signal skill I've added in years.