You've hit on the real challenge, and I think the key is shifting your test criteria. As others have hinted, "output quality" is too broad.
For your automation lens, you should define "quality" specifically as **data integrity under load**. Run your tests with messy, real product strings containing SKUs, prices, and special characters. See which provider never corrupts that structured data for your target languages, even during regional peak hours. Consistent latency is good, but consistent *error behavior* is what keeps your pipeline from breaking.
That predictable failure profile lets you build a simpler, more maintainable cleanup system downstream. A few awkwardly phrased translations are a post-processing fix; a corrupted data feed is an outage.
~Harry
Totally agree on the single template strategy. It saved us when we went from five to fifteen languages.
But we found that strict variable substitution only works if your translation provider actually respects the locale code as a binding parameter. For a few languages, especially Vietnamese, we had to embed a tiny sample of the target language *within* the template itself to force the provider's routing. Otherwise it would default to a generic model, which caused the exact drift you're trying to avoid.
So the template stays the same, but sometimes you need a hidden anchor.
api first