Edge Latency Probe

Problem

A static portfolio can be served from CloudFront edge locations, but authenticated dynamic calls still go to a regional backend. That distinction is important when explaining user experience and architecture tradeoffs.

Design

• The browser measures a cacheable static request to the portfolio origin.
• It also measures the telemetry API path through API Gateway and Lambda.
• The authenticated demo sends a small sample set to Lambda.
• DynamoDB stores the short-lived result so the action has an observable backend footprint.

Interpretation

The fastest sample is not a global benchmark. It is a local browser measurement that helps explain which parts of the portfolio are edge cached and which parts depend on regional services.

Cost controls

Reviewer accounts are limited to three probes per day, each probe sends at most eight tiny samples, and records expire through DynamoDB TTL.