Concealed joist ties (Simpson CJTs) hide the whole connection inside the beam: cut a kerf for the knife plate with a beam saw, rout the flange recess so the hardware sits fully buried, then drill and drive the dowels through from both sides.
The plumb cut at the top of a rafter matches the roof pitch angle; the heel (seat) cut at the bottom is its complement — 90 minus the plumb angle. On a valley against an existing roof, the heel cut also picks up a bevel equal to that roof's pitch.
A wall jack walking up a 14-foot 2x4 can raise a 24-foot wall single-handed — set the jack mid-bay so it can't pivot on a stud, use clear straight lifting poles, add a safety block, and plumb the wall off a laser once it's 90 percent up.