“Ed’s very inventive,” he said. “You don’t see any trace of me-tooism or derivative thinking.”

Mr. Park, who lives on the Upper West Side with his wife and two sons, has been a fixture of New York’s literary scene for 20 years. After graduating from Yale with a degree in English, he earned his master of fine arts degree in fiction from Columbia University, then took a job as a copy editor at The Village Voice. His parents, who emigrated from South Korea in the 1960s and settled in Buffalo, were always puzzled by his literary ambitions, but have been supportive. He worked at The Voice for 11 years, editing its literary supplement and helping to establish writers like Sloane Crosley and Rachel Aviv.

He wrote fiction on the side, and in 2008, Random House published Mr. Park’s first novel, “Personal Days,” about restless New York office drones.

Image From left, Julia Cheiffetz, who recruited Mr. Park and has left Amazon; author Penny Marshall; and Larry Kirshbaum. Credit... Jimi Celeste/Patrickmcmullan.com

He was teaching writing at Columbia when Julia Cheiffetz, then an editor at Amazon, recruited him. Ms. Cheiffetz, a former editor at Random House, had edited “Personal Days,” and thought Mr. Park’s literary connections and talents would help draw writers to Amazon. He was so successful that in 2013 they created the imprint Little A to showcase his books. Amazon, based in Seattle, began as an online bookstore 20 years ago, but it’s a relative newcomer to New York’s publishing scene. The company started its first imprint five years ago, and opened an office in Midtown Manhattan, the hub of the publishing world, in 2011. It has grown to 15 imprints, but its publishing operations remain a negligible part of Amazon’s overall business.

Some literary agents say Amazon’s publishing operation seems to be retreating. Several other prominent editors have left. Jane Dystel, an agent who has done more than two dozen publishing deals with Amazon, said offers from the company — once generous, including even some six-figure deals — have largely fallen to the $10,000 to $20,000 range, and sometimes lower. Some of the writers she represents have returned to self-publishing. “It’s discouraging to those clients,” she said.

Other agents who have done deals with Amazon said their authors’ sales were hurt by bookstores’ ban on Amazon titles.

Mr. Park said he was motivated to join Amazon by the promise of building his own stable of authors and shaping a new imprint to reflect his taste, a rare privilege for a first-time book editor. And he had a deep well of connections to draw on as he pursued authors.