Brinkman graduated from Brown University and earned an MFA from Goddard College. Recently, Brinkman has worked with children as a teacher and tutor, and has led workshops at Mills College and 826 Valencia (a youth arts center in San Francisco). Brinkman is currently employed part-time at the Booksmith, an independent bookstore located in San Francisco.

Upon its release in 2007, Up High in the Trees earned positive reviews in the Washington Post, San Francisco Chronicle, Los Angeles Times, and Chicago Tribune (where it was named one of the newspaper’s "Favorite Books of 2007"). Writing in the New York Times, novelist Madison Smartt Bell noted, "Like Faulkner’s Benjy from The Sound and the Fury, Sebastian is most unusual for the lyrical intensity of his inner life, and the strongest impression this fine debut leaves is his nicely achieved voice, which is moving without being precious." The book also received praised from writers Cristina Garcia, Maud Casey, and Dave Eggers.

Up High in the Trees was released in softcover in the summer of 2008.