During his five-year spell, William helped Benfica to two Primeira Liga titles, forming an efficient partnership with compatriot Ricardo Gomes after arriving as a replacement for another Brazilian, Carlos Mozer.

[1][2] After one season in France at SC Bastia, William moved to Spain with SD Compostela,[3] being fairly used during four years (although he was never an automatic first-choice), two in La Liga and two in the second division.

[4] He then returned to Portugal and Vitória Guimarães,[5] already the bearer of a passport from the country, and retired after two slow years in June 2002, aged nearly 35.

[6][7] In 2016, William was named head coach of newly promoted Gibraltar Premier Division side Mons Calpe, appointing Gibraltar under-19 manager Terrence Jolley as his assistant and overseeing the arrivals of former professionals including Hugo Colace and Michele Di Piedi.

[10] On 13 October 2022, William was appointed assistant coach of Paulo Autuori at Colombian club Atlético Nacional.