When refurbishing my site and setting up Github workflows and actions I wanted to have a way to correlate any of my deployments of code to the statistics I have on the site and any telemetry/data in Application Insights.
Application Insights has an API to add Annotations in your timeline. It adds an entry into your Application Insights instance at a specific time with a set of comments. This annotation is visible throughout many reports such as Sessions, Failures, Events and more, see below.