If, by analogy, the visuals of a movie musical are the "backend" and the audio is the "frontend," then what these localizers do is the equivalent of completely redesigning the entire frontend. Dubbed musicals have an incredible number of constraints in terms of number of syllables, scansion, etc., so the script translators need to be given a tremendous amount of leeway and creative freedom. They're basically lyricists in their own right, in a world where everything's composed melody-first!
In software, this would translate to localization coders being able to (and having the talent to) rewrite the entire frontend logic. And if your software product is going to make multi-millions in new markets by virtue of feeling like it's translated natively, it might be worth retaining native-speaker coder(s) to maintain a branch that parallels (and consistently merges in) your master branch, and rewrites display logic as it comes in. I'd imagine the Googles of the world do exactly this.
In software, this would translate to localization coders being able to (and having the talent to) rewrite the entire frontend logic. And if your software product is going to make multi-millions in new markets by virtue of feeling like it's translated natively, it might be worth retaining native-speaker coder(s) to maintain a branch that parallels (and consistently merges in) your master branch, and rewrites display logic as it comes in. I'd imagine the Googles of the world do exactly this.