Design a Language Translation Service

Functional Requirements:

• Users can input text in one language and receive a translation in a target language.
• The service supports translation between a defined set of popular languages (e.g., English, Spanish, French, Chinese, etc.).
• The system detects the source language automatically if not specified.
• The service provides an API endpoint for programmatic access to translation.

Non-Functional Requirements:

• The system should respond to translation requests within 1-2 seconds for typical sentence-length inputs.
• The service should handle at least 1,000 concurrent requests.
• Translations should be reasonably accurate and fluent for general-purpose text.
• The system should be available 99.9% of the time.
• User data and translation requests must be handled securely and in compliance with privacy standards.