Creating well-paying jobs that entice young, skilled employees to stay in Puerto Rico has been a constant struggle for the island’s economy. Over the past 10 years, Puerto Rico has lost 10 percent of its population as workers leave the island in search of better job opportunities elsewhere. Since Hurricane Maria, another 130,000 people, or 4 percent of the population, have left.

Mr. Oquendo and his co-founder Mr. Figueroa, who is BrainHi’s chief technology officer, met when they were engineering students at the University of Puerto Rico at Mayagüez, on the west coast.

But when Mr. Oquendo graduated, he was one of very few of his classmates who stayed in Puerto Rico. “Basically, all of my friends have left the island one year after they graduated,” he said, citing better job opportunities in the mainland United States.

But Mr. Oquendo is trying to do his part to reverse the tide of out-migration by creating jobs and hiring back some of the engineers who left. And he’s not alone.

One of the companies to graduate recently from Parallel18’s accelerator program, Libros787, moved into offices next door to Parallel18’s. While Libros787 has not moved far from Parallel18’s tight-knit community of start-ups, the company’s founders have made a business of selling Puerto Rican books to the far-flung diaspora.

“We wanted to create a bridge to people living outside Puerto Rico, in the U.S. and around the world,” said Carlos Goyco Blechman, co-founder and chief executive of Libros787.

Libros787 sells Puerto Rican books for about half the price of its competitors, like Amazon. Mr. Goyco is able to sell these books so cheaply because he sells directly from publishing houses in Puerto Rico. According to Mr. Goyco, partnering with publishing houses became easier after Hurricane Maria.