Pros
They have a good 401K and employee stock program. They do everything under the sun so there is a ton of resources at your disposal. If your architectural project ever needs hydroelectric dam you're in the perfect place! If you fill out the proper forms.
Cons
Stantec is a collection of autonomous offices under the umbrella of a massive consortium of figure heads - it feels like working at a franchise. They grow by swallowing up firms which leads to arranged marriages between incompatible offices. The leadership structure is convoluted... there's a gazillion acronyms at the top who switch places with one another. Not a bad place to cut your teeth and learn but know that you will be little more than a number in a computer. One of 30K grains of sand in a corporate desert.