Can someone help me create a coding playlist? (Preferably metal, hard rock, alternative rock)

Slayer & Ice-T: Disorder

10 Years Today - Bullet for my Valentine

Try searching Dancing With The Devil playlist on YouTube

Look up user The Prime Cronus on the youtubes, he makes hour long mixes

Gimme Chocolate - Baby Metal

MONO, vampilia, anoice, world's end girlfriend (more like post, experimental rock)

chon and plini (that's more for chilling out)

GALNERYUS (great voice!)

Chris Huelsbeck, Thomas Detert (retro game music)

From my list i think galneryus (somewhat harder rock, I'm not good with genres) would be the band you really should listen to. Next I recommend chon and plini (both a bit like prog rock, jazz fusion).