The situation in 2012 at PagerDuty was challenging: MySQL had been set up with default settings including Latin character encoding, not unicode. This started causing issues with non-romanized name users, various transliteration functions, and BLOB storage errors. PagerDuty decided to move to a universal character set once and for all.

Less than 1 minute of downtime and only a 2x increase in storage size for affected fields were goals for the migration.

It took some trial and error to get MySQL to store data the right way, and a daring few moments to flip from the old architecture to the new, but in the end the unicode migration went off without a hitch.