What is the dio package in Flutter?
Why Interviewers Ask This
This question targets practical, hands-on experience with Flutter. Interviewers want to see if you've worked with these concepts in real projects, not just read about them. Strong answers include concrete examples.
Answer
Dio is a powerful HTTP client for Dart/Flutter that goes beyond the basic http package. It supports interceptors (for adding auth headers or logging to every request), request cancellation, FormData for file uploads, download progress tracking, and timeout configuration. Interceptors are particularly useful — you can automatically refresh tokens and retry requests transparently. It is the preferred choice for production apps that need fine-grained control over HTTP communication.
Common Mistake
Many candidates answer correctly but can't explain the 'why'. Always be prepared to justify your answer with a concrete example or use case from your Flutter experience.