On 2018-01-08, three new subclasses were released as Unearthed Arcana material. Of those 3, there is the Brute, a Fighter's archetype. At level 7, a Brute gains access to the following feature:
Brutish Durability
Beginning at 7th level, your toughness allows you to shrug off assaults that would devastate others.
Whenever you make a saving throw, roll 1d6 and add the die to your saving throw total. If applying this bonus to a death saving throw increases the total to 20 or higher, you gain the benefits of rolling a 20 on the d20.
Emphasis mine
So for example, rolling a 19 (d20) + 6 (d6) on your death saving throw would count as having rolled a natural 20, getting you back with 1 HP.
But what if the Brute had a friendly Paladin with a +3 aura near him? Or if he was equipped with a Cloak of Protection that grants +1 to all saves? Does this feature of checking if the roll is 20 or higher applies before or after those other bonus?
In other words, if a Brute were to roll 15 (d20) + 4 (d6) + 3 (Paladin's aura), would he gain the benefits of rolling a 20 for his Death Saving Throw?