Async is not "no meetings"
The failure mode of async-first companies is not too many meetings. It is a chat channel that has replaced meetings with the same conversation, stretched over nine hours and legible to nobody.
Async is a writing discipline. If nothing is being written down, you do not have an async culture — you have a slow synchronous one.
Two rules
Everything else we do is downstream of two rules:
Decisions live in writing — in the document, not in the thread that produced it.
Threads expire. If a thread is still open after two working days, it becomes a document or a 20-minute call.
A decision that exists only in a chat thread has not been made. It has been discussed, which is a different and much cheaper thing.
What to write down
Not everything. The list is short: decisions and their alternatives, anything a new joiner would otherwise have to ask for, and anything you have now explained twice.
The "explained twice" rule does most of the work. It is self-triggering and it never asks you to predict what will matter.
We keep decisions in the record they belong to — a deal, a task, a document — rather than a central wiki. The wiki version was tidier and nobody read it.
What we got wrong for a year
We treated "write it down" as a volume target. For about a year the answer to every problem was another document, and the result was a wiki with 400 pages, a search that worked, and nobody reading any of it.
The correction was scope, not effort: decisions live in the record they belong to, and everything else is allowed to stay in the thread and expire. The wiki is now about forty pages and people quote it.
The second mistake was expecting the writing to be good. It does not need to be. A three-line decision note with the alternative that lost is worth more than an essay nobody finishes.
When to call a meeting anyway
When the disagreement is about values rather than facts. When someone is upset. When a decision has been open for two days and the thread is going in circles. When it is someone's first week.
Meetings are expensive, not forbidden. Treating them as forbidden is how teams end up with twelve-message threads that should have been four minutes.