I was able to put this one together by myself.  The corners need to align perfectly at 90 degrees for the peg to go through completely. I used a hammer to gently tap the towel covered corners into place, as I could not do it with just bare hands.  Once the foundation was secured, the placement of the slats was easy.  I did need help lifting the foundation into position on the bedframe.  I have a Casper Hybrid mattress on top and so far so good for 3 weeks.  No noticeable squeaking or shifting.