I'll tell you my stealth build that 1-shots enemies.
1. Sneak is key. Get the x15 damage multiplier perk from daggers. And raise sneak so high that you can even sneak directly in front of enemies in the dark and they won't even know.
2. Raise the base damage of your dagger. It can be done in 2 ways.
2.1 One-handed skill. The first perk increases your damage with all 1H weapons by up to 100%.
2.2 Blacksmithing skill. Craft the best dagger, and sharpen it to increase the base damage.
You are now a terror in dungeons.
Though you may be sitting ducks if you are caught in a situation where you cannot sneak, such as a dragon fight.
To add on to this, use DW daggers, and get all of the perks dealing with DWing and Power attacks, and then use the DW power attack while sneaking... oh man, everything gets one shotted.
Sneak characters are VERY squishy whenever sneak is not an option, and this WILL happen. Sure you have tools to get around that too but still

I recommend getting the Master perk of sneak, which makes you be hidden for a second as soon as you sneak. I am not sure as I haven't gotten it yet, but I believe that this will allow you to effectively run around a corner and lose aggro on enemies.
Also get a lot of Invisibility potions to do the same thing. Just get a bunch of Vampire Dust and Ice Wraith Teeth.