Understood on the happiness engineering role.

Don't get me wrong, I think you can give yourselves any title you want, but when listing job postings you're just creating barriers by using non-descriptive, non-standard titles. Your potential applicants have to check the job description for "Account Engineer" to see if this is something they would be interested in (for most it won't be), if someone was actually looking for a client/account director role they might not notice this one because of the "engineer" part, and if someone was looking for a blended support/coding role they might miss "Happiness Engineer" while scrolling down the page.