Once #22600 is in place, Spring Boot provides an easy way to configure an ApplicationStartup implementation for collecting startup metrics. The only available implementation is tied to Java Flight Recorder, which fits well for profiling use cases, but not when it comes to buffering data and re-exporting it to metrics systems once the infrastructure is in place at the application level.
This issue is about providing a Spring Boot specific ApplicationStartup implementation that buffers and provides snapshots of collected steps. This could be used to re-export data to metrics systems or make this data available on actuator endpoints.