We at Axelerant have been contributing to Drupal in our own ways since a long time. In fact, I worked as a full-time contributor to Drupal a few months after I joined. This was around the time Drupal 8 was almost done and it is thanks to Axelerant I could contribute what I could at that time. At the same time, there was community focus around incentivizing contributions and there were a few website (like drupalcores) to track contributions.