"Kim knew that, but he left last month." Every company hears this. The code stayed and the story left. Why this exception handling is here, why this batch job runs at 3 a.m. Nobody knows the reason, so nobody will touch it.
Why documents never worked
"Please leave documentation before you go" always fails. The person leaving has already forgotten what matters (it is obvious to them), and the people staying do not know what to ask. Tacit knowledge is not knowledge you write to an outline. It is knowledge that surfaces while you work.
Picked up in the flow of work
So Platty does not ask people to write tacit knowledge down separately. It picks it up in the flow of work. When someone is working with AI and something worth keeping comes out, one sentence is enough. "Add that to Platty." The knowledge is attached to the related epic and code location and stored as a memory.
So rumor cannot pass for truth
That said, taking people at their word and writing it straight into the truth would pollute the SSOT. So memories start in a proposed state. Once another team member confirms one, its trust level rises, and anything that contradicts the code is flagged as contradicting it. When a memory is used in an answer, its level is shown alongside it.
The more it accumulates, the harder it is to leave
What happens after a year of this? You become a company where the things the code does not tell you, the reasons behind decisions, the operational tricks, the record of failures, are attached throughout the system. A new hire starts out having inherited their predecessor's head. Departures are still a loss, but no longer a disaster. Knowledge stays with the company, not with the person.