Easy to put together (if you don’t have a migraine and read carefully their silly illustrations type instructions). But seriously, after initial frustration, this is a very sturdy stool, especially for the price point. 
One hint, as my husband always reminds me...don’t tighten the screws too tight until you have it together. Then, go back and tighten them all. Also, on the leg ring. Do one, then the opposite, letting it sort of free hang. Once the two opposite sides are attached you can apply some gentle pressure to get the out to get it straight and secure with the remaining screws.