/i18n

Take an app from one language to many, and keep it there. Written after shipping 36 languages in an iOS app; the traps below each cost real time and none of them announce themselves — a missed string looks perfect in English.

The order of work

1. Humanize the source language first. Translating is per-language cost: fixing an English sentence after the fact means re-translating it in every language. /humanize on the long copy, then translate.
2. Extract, don't hunt. Get the platform's extractor to produce the key list. A grep for quoted strings finds prose and misses everything typed wrong (see the type rule below).
3. Translate in batches, machine-first, with a validator that refuses a batch dropping a format specifier or a plural category.
4. Look at it running, in a right-to-left language and in a long-word language (German, Finnish). A language that is merely declared is not a language that works.