Is your product available in many languages? Did you hear anecdotes about poor translation quality but felt helpless about how to approach this? This talk will give you insights to the challenges YouTube was facing when scaling the product to more than 70 languages, to serve their international audience. It will introduce user metrics that help measure and understand the quality of language translation used in products. It will highlight the internationalization challenges we faced at YouTube, and how we came up with a new approach to solve them.