The T-44-100 is a Soviet Tier VIII Premium medium tank and shares many similarities with the standard version, the T-44. Of course, while all the modules need to be researched for the standard vehicle, the T-44-100 comes by default with the Elite status, and ready to battle!
As the T-44-100 is a prime example of a medium tank, it can potentially take over many roles on the battlefield. Most of the time though, you'll be playing a supportive role, trying to exploit the mistakes of the enemies, and taking crucial positions quickly. Watch the minimap regularly, it will help you find out where you're needed the most.
The armour layout is typically Soviet – a sloped front, a strong turret, and spaced armour on the side. The hull itself can't withstand much punishment, unless you're fighting lower tier vehicles, but the turret can bounce a lot of shots. Higher calibre guns however, will punch through it easily, and penetrating hits will often result in a damaged or even destroyed ammo rack. Increase the chance of a ricochet by moving back and forth slightly, and make it difficult for the enemy to aim properly.
In terms of firepower, this Soviet medium certainly doesn't need to hide. With a damage per shot slightly above average, and a good rate of fire, you can rest assured you can support or charge lonely tanks just fine. The 100mm gun performs best in close to mid-range; at longer distances the accuracy is not good enough to hit enemy tanks reliably. It's best to brawl with other medium tanks or circle heavy tanks and tank destroyers.
Because the T-44-100 is most effective in close to mid-range, it makes most sense to improve the gun performance as such. Of course, you can also go for Coated Optics if you like to spot opponents earlier, but there are many vehicles that are way better suited for this task.
A fairly common choice of crew skills. As with most vehicles, the Repair skill is one of the highest priorities, together with Sixth Sense. While Safe Stowage is selected as second perk in the table, you can also make it your first if you feel like the ammo rack is too weak. Snap Shot, Smooth Ride, and Brothers in Arms aim to improve your gun's parameters, increasing your chance to land a hit.