Not only was it made with Blender, the final renders were done with Blenders semi-realtime Eevee engine rather than its max-fidelity Cycles engine. That reduced the compute required by orders of magnitude - the director said a render farm wasn't necessary because his local workstation could produce final-quality 4K frames in 0.5-10 seconds.
"Proper" production renderers like Cycles do look better of course, but having an alternative which is viable on a shoestring budget is very valuable.
"Proper" production renderers like Cycles do look better of course, but having an alternative which is viable on a shoestring budget is very valuable.