"👨‍👩‍👧‍👦".length is 11. That emoji is one character on screen, seven Unicode code points, and 25 bytes on the wire. Which of those numbers a social network measures your post against depends on the network — and if you pick the wrong one, you either reject posts that would publish fine or accept posts the API will refuse hours later, when the thing is already scheduled. This is what we learned building a publishing API against thirteen networks, with the numbers taken from the real APIs rat...