Like an angry cyborg ninja with something to prove, CD Projekt Red has taken a pair of bloat-cutting mantis blades to Cyberpunk 2077's formerly overwrought crafting and upgrade system. It now couldn't be easier to keep a favorite iconic weapon up-to-date as your V makes the long march from level one to 60.
Cyberpunk's loot system used to feature both rarity tiers and leveled damage numbers, with cool or unique weapons quickly getting leveled out of usefulness. You could boost a weapon's leveled stats at a rapidly increasing cost, and improving a weapon's rarity tier required significant investment in one of the game's attributes, Technical Ability. That's all gone now in favor of a much simpler system, with easily upgraded powerful Iconic weapons taking center stage.
Cyberpunk 2077 weapon tiers
CDPR has removed leveled damage from weapons entirely. Now all weapons of a shared model (like Nova revolvers or Unity pistols) do the same damage at corresponding tiers, with Iconic weapons adding worthwhile effects and modifications. Similar to the different leveled weapon types in Skyrim (iron, glass, daedric etc.), you'll see more weapons of higher tiers as you keep leveling up.
As a note, weapon mods also have tiers, and they need to be equal to or lower than the tier of a weapon to be attached. A tier four sight can go on a tier five gun, but not on a tier three gun.
Unique or Iconic weapons are the only ones that can be upgraded to higher tiers, and these are generally the best weapons in the game. They have fewer mod slots than standard weapons—Iconic weapons can't take stat-modifying weapon mods, and are limited to optic and muzzle mods, if that. However, the intrinsic bonuses of most Iconic weapons easily outpaced the best stat-modifying mods I found in my time playing the game.
Cyberpunk 2077 Crafting requirements
You no longer need to invest in Technical Ability to craft weapons or upgrade Iconic weapons' tiers: you only need sufficient materials and, in the case of crafting a whole new weapon, the proper item schematic. Both can be found in random loot and as quest rewards.
You can quickly acquire crafting materials by dismantling weapons and armor pieces—the latter especially is consequence-free since every new clothing item you collect gets automatically added to your transmog wardrobe. You can still visually wear any piece of clothing you've dismantled, even if you no longer have the item. As you'd expect, the tier/color of item you dismantle will determine that of the materials you get.
You'll want to strike a balance of dismantling your loot for materials, and selling it for eurodollars. Dismantling is bound to the "Z" key in your inventory, and the crafting/upgrade menu can also be accessed from your inventory.
One more tip: early in the Technical Ability perk tree there's a perk called Easy Day that awards you +25% crafting components from looting. Since you can respec perks at any time, consider grabbing this one before a big fight if you're in need of some more materials.
You use the same pool of crafting materials to upgrade your Cyberware at Ripperdocs. Quickhacks have their own pool of Quickhack components. You can sometimes find these as loot on enemy Netrunners, but for the most part they can be purchased from hacking-focused vendors and are awarded through the Breach Protocol hacking minigame.