What is the MOST operationally efficient way for the company to determine which internal call is causing the slow response times?
Use Amazon CloudWatch.
Use AWS X-Ray.
Use AWS CloudTrail.
Use VPC Flow Logs.
Explanations:
Amazon CloudWatch provides monitoring and logging for AWS resources but lacks the granularity needed to trace specific internal calls and their performance metrics across multiple services.
AWS X-Ray is specifically designed for tracing requests as they move through different services, allowing for detailed insights into where bottlenecks occur in the application architecture, making it the most effective tool for diagnosing slow response times.
AWS CloudTrail logs API calls made within the AWS account, but it does not provide performance metrics or tracing capabilities for internal service calls, making it insufficient for diagnosing slow response times.
VPC Flow Logs provide network traffic data but do not capture detailed application performance metrics or internal request tracing, which limits their effectiveness in identifying slow response times in API calls.
From my point of view, the answer is:
Use AWS X-Ray.