If you farm bosses successfully in BL3, the boss will drop unique legendary items for you. That's the reason why players want to find out the best places to farm bosses.

 
 

How to Farm Bosses in Borderlands 3 : Step by Step
1. Beat the Boss the first time and complete the mission
2. Head back to the boss location
3. Beat the boss again
4. Get the Loot
5. Quit out of the game
When you restart your character save you will be at the closest save point to the boss
Beat the boss again. All you need to remember is that you will want to clear any loose ends that you have on the mission before trying to farm.  Whether that’s heading back to Sanctuary to speak with an NPC or something else, you will want to complete the story mission completely.  Once you have you can fight the bosses of Borderlands 3 over and over and they will drop loot and cash each time.
 
Borderlands 3 Best Bosses to Farm
Mouthpiece
In Chapter 3: Cult Following, you are going to come across Mouthpiece in Pandora – Ascension Bluff. The ground where you will meet the boss is very dangerous as there will be speakers around everywhere, even in the pillars, and as they glow red, this means to get away from there as explosions are about to happen. You need to be quick to move around and attack him in order to defeat him. It doesn’t have to be immediate, but, on defeating Mouthpiece, you are going to be rewarded with a Shotgun, Mindkiller or a Gatling Gun which is an Assault Rifle.
 
Gigamind
Gigamind is one of the earliest boss encounters you will come across. What makes Gigamind such a good boss to farm is how quickly you can get back to him and how simple he is to defeat. Gigamind is located at the end of the Hostile Takeover questline and cannot be encountered until you complete it. Gigamind not only drops a massive amount of loot when defeated, but he also has a unique gun that is exclusive to him called the Smart Gun XXL, a Corrosive SMG that delivers massive damage and has unique perks.
 
Crushjaw
Crushjaw is my personal favorite when it comes to farming Legendaries, though you need to get through the entire Cathedral of the Twin Gods to get to his locations. It's filled with Badass and Anointed enemies, so if you are just starting your adventure on Mayhem 3 it may be a challenge to get there. There is an alternative way to reach him; you can fast travel to The Great Vault and just head back to the Cathedral of the Twin Gods. There are no enemies at all, but there is no checkpoint either so you need to fast travel to The Great Vault every single time. On top of the high Legendary Drop Chance from Crushjaw, there is a big Chest behind him, and there is a chance for Eridium chest to spawn in the room as well.
That is the guide for the locations to find best bosses and grinding Legendaries. If you need to buy cheap BL3 Money, we 5mmo.com is also here for help.