Building a Next.js app in 7 different languages with i18n

i18n is one of those features that looks trivial in the docs and terrifying once you try to retrofit it onto a real project. Here's how I did it without rewriting the world.

The approach

• App Router with route-based locales: /en, /de, /fr, etc.
• A single messages/<locale>.json per language. No nested folders, no over-engineering.
• next-intl for the client-side bits. Picked it because it plays nicely with Server Components.
• A fallback locale so missing keys never break the page.

What I'd do differently

• Start with two languages, not seven. Translation quality matters more than coverage.
• Don't auto-translate marketing copy. I tried and it showed.
• Ship the language switcher last — people care about it less than you'd think.