As AppNeta’s developer evangelist, I work with customers in five different programming languages to monitor application performance. But it's our community-developed Drupal module that has seen some of the most enthusiastic adoption. About a year ago, I decided to port it and learn Drupal 8 the hard way.

Building a performance monitoring module is interesting work because it needs to extract information from many components without introducing unnecessary latency or errors. I'll run through the module's iterations and explain why I made certain decisions, or why I went back on others, tying it all back to what this project has taught me about Drupal 8's architecture and development process.

I'll be covering:

* Contemporary monitoring tools and strategies in Symfony and Twig
* The components in Drupal 8 that can be monitored
* Building a performance-monitoring Drupal 8 module via dependency injection
* Monitoring a large-scale, heavily cached Drupal 8 environment