You just chopped a glorious pile of green. Don’t dump it into the salsa bowl yet! Not unless you’re serving it in the next ten minutes.
Cilantro gets wilty and sad if it sits in acidic tomato juice. It starts to look like a forgotten salad from three days ago. Tragic.
Add it at the very end. Give it a final stir. Let it taste the victory of being the last ingredient. That’s when the magic happens.