Optimize middleware for large datasets

**Problem**
When working with services, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

No files, tests, or entry points are named. First locate the middleware and service error-handling paths, then clarify whether the requested work is error-message detail or middleware performance for large datasets. Done should include a defined error-message improvement with coverage for the affected cases.

Written by the indexing model from the issue text.