Do you have that one expert whose resignation letter would keep you up tonight?

Most managers do. It’s that person who holds the "secret sauce" to your operations, the stuff that isn't written down anywhere.

The reality is that there is no magic wand for this, and there is certainly no "copy-paste" button for a human brain.
Trying to fix it with a retention bonus or a salary bump is usually just a temporary fix; it buys you time, but it doesn't solve the underlying risk.

In my experience, the only practical way forward is a focused approach: identifying, capturing, documenting and haring that critical knowledge: the specific tools, techniques, and "know-how" that currently only live in your experts' heads.

The goal isn't to make people feel replaceable. It’s to ensure that when someone eventually moves on, the department doesn't stall. It changes a potential crisis into a manageable transition.

Managing the knowledge means managing the risk and finally getting a decent night's sleep.