Lesson learned post
[MISTAKE, one line]. Here's what happened: [CONTEXT] Here's what I did about it: [FIX] Here's what I'd tell someone starting out: [LESSON]
Filled example
Shipped a pricing change without telling existing users first. 6 people emailed angry within an hour. I reverted for existing users and grandfathered everyone. Lesson: grandfather your first 100 customers, no exceptions.