We are wondering if there is any way to programmatically manipulate dashboards, alerts and other stuff that you normally set up using the Stackdriver UI. It would be great to keep the definitions of our Stackdriver objects in Git and deploy them using an API. Is there such a functionality available which we couldn't find googling?
Yes. Most of these things can be managed using the Monitoring API. There is support in that API for managing metrics, groups, notification channels, alerting policies, etc. Some of these can also be manipulated using the Cloud SDK (see the documentation for gcloud alpha monitoring). As of this writing, it does not look like the endpoints for dashboards are widely publicly available yet, though double-check the API reference if you come across this answer from a later date. For capabilities that are not available, you may want to consider reaching out to the discussion forum to put in a feature request or to be added to Early Access or private Alpha features if available.