From the pattern:

This cardigan is worked back and forth in one piece from the bottom up to the armholes, then the Back and Fronts are worked separately. After shoulders are joined using a three-needle bind-off, stitches for the Sleeves are picked up and the Sleeve cap is shaped with short rows and then joined to work in the round from the top down. The neck edging and button loops are added during finishing.

The stitch pattern is presented in chart form only.