This is a seamless sweater. The body and sleeves are each worked separately in the round from the bottom up. The yoke is then worked in the round with short rows used to raise the back neck. Underarm sts are placed on waste yarn and later joined using a three needle cast off, resulting in a seamless garment.

For more information, see: https://www.knitnowmag.co.uk/2018/12/27/knit-now-97-out-now/