Failure posts perform well, which is why most of them are fake.
The template: something went wrong, the author was humbled, they learned a valuable lesson, they are now wiser and grateful. The failure is small, safely in the past, and resolves into growth by the third paragraph.
This is a success post in costume, and it is transparent.
The tells
The failure is flattering. "I shipped too fast." "I cared too much about quality." These are strengths wearing a disguise.
It is fully resolved. The lesson has been learned, the process fixed, the author improved. Real failures are often still unresolved when you write about them, and the resolved ones took longer than the post implies.
There is a moral. Five bullet points of lessons at the end. Real failure is less tidy and usually teaches one thing, awkwardly.
No consequences. Nobody was affected, nothing was lost, nothing was at stake. Then it was not a failure, it was an inconvenience.
What an honest one looks like
The scheduled job ran twice for some users last Tuesday. Two people got duplicate posts on LinkedIn under their own names.
The cause: a retry fired while the original run was still going, and nothing held a lock. I had thought about this case and decided it was unlikely enough to leave.
I have added a lock now. I do not have a good answer for why I made that call originally, beyond wanting to ship.
Shorter, less flattering, no lesson section. Also considerably more credible, and the only version anyone will remember.
The three qualities that make it work
Specificity. Actual thing, actual date, actual consequence. Vagueness is the main tell of an invented failure.
Cost. Say what it cost. Users affected, hours lost, money. Without cost there is no failure.
Unresolved parts. If you still do not know why, say that. "I have not figured out the root cause" is more honest and more interesting than a tidy explanation you are not sure about.
What not to do
Do not write about a failure you have not accepted. It will read as defensive, because it will be.
Do not blame a person. Even obliquely. Even if it is fair.
Do not write about a failure that is still live. If customers are affected right now, fix it and communicate directly. A public post during an incident is about you rather than about them.
Do not manufacture one for content. People do this. It is obvious and it is worse than posting nothing.
Why it matters more than it sounds
Everything else you write is weighted by whether people believe you.
A person who has written one genuinely unflattering post gets read differently forever after. Their good news becomes credible, because they demonstrated that they would have mentioned the bad.
That is the actual return on honesty here, and it is why the performed version is self-defeating. It buys the appearance of the thing while spending the trust that makes it work.