Supporting many languages sounds like a feature you add. In a health product it is closer to a constraint that shapes everything, because the people who most need a document explained are very often the people least served in the language it was printed in.
What is genuinely difficult
- The document and the conversation are in different languages. The report is in English; the question about it is not.
- Values must not be translated. Units, numbers and the laboratory’s own range stay exactly as printed — they are what is on the paper in the person’s hand.
- Register is harder than vocabulary. Clinical language carries weight. A translation that is technically accurate and tonally wrong can frighten someone for no reason.
- Spoken input is not written input. People say things they would never type, and the spoken form of a language can differ sharply from its written one.
The rule that fixed the worst bug we have shipped
Each message carries its own language. An account-level setting describes a preference, not a constraint — and when the read-aloud feature used the account setting instead of the message’s own language, it read only the English words out of an answer given in another language. The oldest person testing the app found it within minutes.
It is a good illustration of the general principle: in a multilingual product, anything that decides language globally will eventually be wrong locally.
This article explains how our technology works. It is health information, not medical advice.