There’s a way to get your character to be functionally bullet-proof in Cyberpunk 2077, but it’s not quite a build (you don’t need to invest any attribute points or perk points to do this) and it’s not really an exploit, either (you’re just using in-game items the way they were designed to be used). Still, it’s incredibly broken and trivializes most of the game, so use it at your own discretion.
The key to this is getting your hands on an Armadillo clothing mod, which doesn’t have a static drop location, but there’s a fair chance you’ll find one while completing NCPD Hustles, Gigs or Side Jobs, so just keep an eye out and loot diligently as you clear map markers.
Once you have the crafting spec for the Armadillo mod, you’ll be able to craft said mods for a measly 7x Common Components and 2x Uncommon Components (or less, depending on what perks you’ve assigned). The cost of this is just a little more than what you’d get for breaking down a can of soda, which, to put it into perspective, can be purchased from many vendors and bartenders for a mere €$10. Suffice to say, this is not a resource-intensive endeavor at any stage of the game.
Crafting an Armadillo mod may seem like it’ll yield common mods, but despite the crafting icon, you’ve got a random chance to create a common, uncommon or even rare mod every time you craft one, with the rare mods giving about 50% more Armor than the common varieties. Despite the names of these item tiers, “rare” isn’t all that rare when it comes to crafting Armadillo mods - craft twenty or so mods and you should end up with enough rares to fill up an armor piece or two, and the excess common and uncommon mods can be scrapped to recover most of the resources you used to create them. In fact, you should see a net gain in uncommon mods by doing this, even with no perks spent in the Crafting skill tree.
Another variable is your own level, as the Armor on each mods scales with it. At around level twenty-five, rare Armadillo mods should yield about 100 Armor each even with little to no investment in the Technical Ability attribute or Crafting skill tree. This makes each Armadillo mod roughly comparable in terms of Armor to a set of outer torso armor, and with even a few mod slots filled, you can easily double your Armor value. Just craft a dozen or two Armadillo mods, keep the rares, and break down the rest.
While throwing some rare Armadillo mods into whatever armor you find is all well and good, we’re going for “broken” here. For that, you’ll need legendary armor. The base stats of this armor is irrelevant, but each piece of legendary armor can spawn with 4x mod slots (inner torso and outer torso) or 3x mod slots (every other type of armor). That’s a maximum of twenty mod slots you can have in your armor at one time, and if you do the math, a level twenty-five character averaging 100~ Armor per Armadillo mod will end up with around 2,000 armor, plus whatever they get from the base armor itself, attributes, perks and cyberwear. All told, you’ll likely end up with over 2,500 Armor easily, a number that’ll only increase as you level up… just be sure to recraft new mods a few times as you level up to fifty and you’ll remain untouchable.
As for the legendary armor itself, it spawns throughout the world in static locations, although there are two things to keep in mind: First, you must complete the quest The Heist to open up Night City, as most of the armor lies outside of Watson. There are a few pieces you can pick up within Watson, but for a full suit of legendary gear, you’ll need to travel. Second, the quality of legendary armor is not static. In addition to scaling to your level when you pick it up (as most items do), legendary armor will also randomly spawn with 0-3 (or 4, if it’s torso armor) mod slots. Legendary armor with insufficient mod slots isn’t fit for purpose, but fortunately you can just save near the armor, pick it up, see if it has the correct number of mod slots, and if not reload and pick it up again until it does.
The locations of legendary armor can be found on each piece of legendary armor’s page in the Legendary Armor Locations section of the guide.
Getting yourself a massive Armor score by stacking Armadillo mods will make you functionally bullet-proof, with even skull’d enemies struggling to damage you. Keep in mind, however, that this has limitations: melee attacks are still surprisingly painful, for whatever reason, and Armor is not the same as Resistance, so other forms of damage may still affect you.