Tallis Gomes had spent four years as the CEO of EasyTaxi, the “Uber of Brazil,” when he decided in 2015 to aim the same concept in a new direction—the beauty industry.

His on-demand services platform, called Singu, allows customers to summon a masseuse, manicurist, or other beauty professional to their home or office. Scheduling is done by an algorithm factoring in data from Singu and third parties, including location and weather. The professionals see fewer customers than they would in a shop, but they make more money because they don’t have to cover the overhead. Gomes says the algorithm can get a manicurist as many as 110 customers in a month, and earnings of $2,000—comparable to what a lawyer or junior engineer might make.

—Nanette Byrnes