The pullover is worked flat from the bottom up. Front, back, and sleeves are worked separately and seamed. Stitches are picked up at the neckline to work the 1x1 rib neck trim.
All charts are worked flat. Odd (RS) chart rows are read from right to left. Even (WS) chart rows are read from left to right.
1x1 Rib pattern starts with a knit on the RS of the back panel and a purl on the RS of the front panel to ensure pattern continuity at the side seams.

Yarn
Phoebe by Quince & Co (100% Merino Wool; 300 yd 275m/100g)
3 (3, 4, 5, 5) (6, 8, 9) skeins Celestite (A)
1 (1, 2, 2, 2) (2, 3, 3) skeins Turquoise (B)
1 (1, 1, 1, 1) (1, 1, 2) skeins Red Jasper (C)

Needles
One pair in size US 4 3.5 mm for cast on
One pair in size US 6 4 mm for body and sleeves
One 16” circ in size US 6 4 mm for neck trim
Or size to obtain gauge

Notions
Stitch marker(s)
Stitch holder or waste yarn
Tapestry needle