# Callback investigations
- Airflow
- Can
- on_success_callback
- on_failure_callback
- sla_miss_callback -- a "soft" timeout
- on_retry_callback
- on_execute_callback
- pre_execute
- post_execute
- Connect to Airflow metadata database on demand
- Cannot
- detect when jobs are queued
- Trigger callbacks from the Airflow metadata database
- Github: webhooks can pretty much do anything we'd like -- kind of like Slack event listener. Many event types are supported, for example
- Commits to a branch (this could be used for listening to merges)
- PR (open, close, comments)
- Jenkins
- Can add post build scripts to post to api
- post build scripts can send over the build url which contains all info (such as params, status) about the build.