This lick is a fast, fluid-sounding legato run based on the D Dorian mode (D E F G A B C), courtesy of Gus G.
I rely on consecutive hammer-ons and pull-offs to articulate many of the notes and use finger slides to seamlessly shifts positions as I ascend the fretboard. Using finger slides allows me to continue up a single string without having to interrupt my smooth, legato phrasing with an unwanted pick attack.
Each position shift is deliberately selected for maximum efficiency, and in each case you'll notice the index finger only needs to slide up one fret, whereas shifting at any other spot on each string would require a two-fret slide.
The single-fret slide is ideal here because it reduces the chance that I'll overshoot the target note when performing the lick at breakneck speed.
The tempo is 210 beats per minute, 125 for slow practice.