2 employees have rated Companhia de Saneamento Básico do Estado de São Paulo - SABESP Chief Executive Officer Gesner José de Oliveira Filho on Glassdoor.com. Gesner José de Oliveira Filho has an approval rating of 100% among the company's employees. This puts Gesner José de Oliveira Filho in the top 10% of approval ratings compared to other CEOs of publicly-traded companies.