Extremely important: If you use mysqldump, make sure it's also using utf8mb4. There is a very high chance it defaults to utf8 and silently corrupts your data.
I love MySQL, but the fact that they didn't make utf8mb4 the default for mysqldump (instead of utf8), when they created utf8mb4 for database use... is one of the most irresponsible and negligent pieces of engineering I've seen in a long time, considering the amount of data worldwide backed up with mysqldump.
The fact that a program designed solely to back up databases would default to silent corruption like this is mind-boggling. At least they've fixed this in the future for MySQL 8.0.
is your company one of them?
With this I had used a backup and nobody even noticed the problem for three weeks, thankfully I had some more direct backups too...
Since the complaint here is of corruption that is silent, the level of testing required to catch it would be extraordinary.
mysqldump --default-character-set=utf8mb4 -u user database > dump.sql
right?