The name should give you a pretty good idea of what you're doing: cloaking and stabbing. The mines are just an added benefit, and really the only useful major investment you can make.
This loadout is designed to infiltrate bases undetected. The tactics are simple. Step 1: Get near an enemy base, preferably approaching from an odd angle. Step 2: Get into the enemy base. Step 3: Hack an equipment terminal. Step 4: Place a mine next to the terminal. Repeat Steps 3 and 4 with vehicle terminals and turrets, resupplying your mines as needed. Step 5: Stab anyone who gets in your way. Step 6 (optional):Hack a vehicle terminal and pull out a Sundy so your teammates can spawn on it.
If you're using this setup, you'll be getting kills in one of two ways: (a) stabbing someone or (b) someone trips your mine. Always remember that it takes two (2) hits with a knife to kill an unharmed infantryman, so try to avoid uncloaking until you're sure you've got the drop on your enemy. Under no circumstances should you fire your gun, especially not your rifle. Shooting is a good way to get yourself killed, even if your weapon is suppressed (which it shouldn't be).
As for Certs, well, the basic setup is rather simple: level up your basic cloak and your hacking skills, then save up for your anti-personnel mines (Should total somewhere around 230 Certs). After that (or possibly before), I'd recommend increasing Nanoweave Armor to get yourself out of the occasional tight spot. Beyond that, it's all specialization; just upgrade whatever suits your ninja the best. Whatever you do, don't even think about upgrading your weapons. It's far too expensive and the loadout is designed to eliminate the need for weapons fire.