Scaling ThumborΒΆ
Bernardo Heynemann wrote an article detailing this at Scaling Thumbor;
Yipit has detailed how they scale thumbor at their engineering blog;
Square also posted at their engineering blog about how they generate dynamic images with thumbor;
99 Designs also has some info on their architecture using thumbor and amazon at their engineering blog.
heycar also has some info on their architecture using thumbor on with CloudFront and Kubernetes at their engineering blog.