Worked in web dev for the past 15 years or so, met Drupal when it was 5 versions old.

Back-end work for a multi-billion-pageviews site, nbcolympics.com (Sochi 2014), for which I created many custom modules and shamelessly hacked the image module in core for performance/security reasons, right there in production. Broke the site, too.

Other important Drupal projects I've gotten my hands on: sheltercluster.org, facilitar.io, golfchannel.com, funnygarbage.com, sanfrancisco.travel, and several Pfizer sites.