It engine brakes quite well, especially around town at lower speeds in lower gears. According to Wikipedia there are several ways modern diesels create effective engine braking:
https://en.wikipedia.org/wiki/Engine...ng?wprov=sfti1
I imagine with the advantage of a very flexible valve train, they could force the engine to operate in a similar fashion to the heavy diesels "Jake Brake" by releasing compression.
I drove truck during college as a summer job, and though the International 466 I drove didn't have a Jake Brake (and had less power than my 335d!) you could still get enough engine braking out of it to make it worthwhile downshifting on long hills to take some load off the service brakes.