A Strange Habit of Mind by Andrew Klavan

English professor and ex-spy Cameron Winter confronts a Big Tech billionaire to solve the suspicious suicide of a former student
The world of Big Tech is full of eccentric characters, but shamanic billionaire Gerald Byrne may be the strangest of the bunch. The founder of Byrner, a global social media platform, Byrne is known for speaking with vague profundity and for dabbling in esoteric spiritual practices; he wears his hair in a long black ponytail to reveal a large flower tattooed on his neck; he's universally admired as a visionary, a philanthropist, and a devoted husband and father. And every person who gets in the way of his good work seems to die.
When a former student commits suicide, English professor and ex-spy Cameron Winter takes it upon himself to understand why. The young man was expelled from the university in an unfortunate episode that left Winter sympathetic to his plight; after a prolonged silence, he reached out to his teacher...