The act of hammering out programming code insanely fast.
Edwin: "Hey Jon, let's hang out tonight."
Jon: "Sorry, can't tonight; going to do some keyboard shredding."
Miguel: "Hey do you hear all that keyboard clicking noise?"
Edwin: "That's just Jon keyboard shredding. Don't disturbed him; he's in the zone."
Jon: "Wow look at that nerd's long hair and neck beard. He must be a keyboard shredder."