It was a mix of Blender’s Cycles and Eevee. The environment was rendered in Eevee because it took so much less time to render and the actual excavator was rendered in Cycles, and then the shots were composited in. Kent made this gif to show it off a bit.
https://blog.cgcookie.com/wp-content/uploads/2021/02/uploads1612557192824-comp-breakdown.gif
