Why sneak behind somebody and stab them in the back when you can shoot them in the back.

Level 17: True Stealth

Nobody can deny that you are the sneakiest of the sneakiest. Your max DEX level is raised to 24 and you gain an extra 5 to your DEX modifier.

Back Shot

Starting at 3rd level, once per turn, if you attacked with a ranged weapon, instead of using a Sneak Attack you can roll 1d20 + your DEX modifier. If this roll is equal to or exceeds the enemies armor class, you roll Sneak Attack damage and multiply the result by 2 (Sneak Attack Damage X 2) and you can't use Sneak Attack for the rest of your turn. If this roll is less than the enemies armor class, you deal no extra damage and can't use Back Shot or Sneak Attack for the rest of your turn.

Percise Shot

Starting at 3rd level, you are deadly against any enemy that doesn't notice you. When using a bow, you have advantage on attack rolls against any creature that hasn’t taken a turn in the combat yet. In addition, any hit you score against a creature that is surprised is a critical hit.

Expert Hider

If you kill a creature, and if you can hide. Then you can use your reaction to take a Hide action.

Archer's Eyes

3 times per long rest, you can visualize just by hearing them where an enemy is. You gain advantage with hitting an enemy without cover and don't have any loss to the hit modifier when trying to hit something behind cover.