The Borrowed Language
Shoppers switch the catalogue from English to French, but some product pages keep the English title and description. A different product may appear in the correct language. The problem also seems to depend on which language was used first after the service restarted.
The bug report
You get the whole project — a React front end, an Express API, and Mongoose models — opened in a browser editor. Reproduce the symptom by reading the code, change what’s wrong, and run the hidden tests to prove it.
What the fix must prove
- returns the requested translation on a cold lookup
- reuses cached data for repeated equivalent requests
- keeps product translations independent across warmed cache entries
- rejects unsupported locales
- returns 404 rather than caching a missing product