This is THE ultimate meta build for your [Smeeta Kavat]. While an 8 forma Smeeta may not appeal to most people, some of us love our pets more than others.
Your companion should NEVER die with this build.

Damage is not a priority in this build, as with most Smeetas; there are better option companions for building something to help fight.
Now if you want max buffs, and never have to worry about your Kavat going down, this is the way.

Link Armor, Link Health, and Link Shields are self explanatory. You will share health, shields, and armor with your current Warframe. At max level, these mods will make your Warframe's health and shields look weak compared to your cat.

[Charm] is also a given, that is the reason you are using a [Smeeta Kavat]. The random buffs it gives makes the Smeeta one of the best, if not the best, companion in the game.

This is also the reason we are using [Tek Enhance]. Increased duration to your [Charm] ability. As well as giving you a 6m zone that inflicts damage to enemies.

[Tek Assault] increases the range and damage of the Tek mod set. If your Kavat wasn't already unkillable enough, this will really give it "9 lives", giving it the chance to ignore death completly and become immune.
[Medi-Pet Kit] is also just for extra outrageous survability.

[Shelter] has helped me many times, creating a shield around your warframe while you revive your allies.

[Fetch] is super important, and one of my favorite mods. Your Smeeta will run around and scoop up the items in your vicinity that you missed, making sure you are always picking up the max amount of items and resources in your route to the extract.

Have fun, treat your pet with love, and get to formaing it 8 times.