Following military service as an officer in the Israel Defense Forces, Zaki embarked on a career that has included party politics and work with organizations promoting peace and challenging the Israeli occupation of the Palestinian territories.
After completing a law degree at the Hebrew University in Jerusalem, he became the media and political advisor to former Justice Minister and peace camp leader, Yossi Beilin. He took part in the talks that formulated the Geneva initiative, and was a main spokesperson of the initiative.
He later entered party politics and was elected to be the chair of Young Meretz, Israel's progressive party, and was a candidate to the Knesset, Israeli parliament, in the party's list in the 2009 national elections.
Zaki is an alumnus of the American Council of Young Political Leaders exchange program (2005). In 2008, he was named among Israel's most prominent young professionals by Forbes Israel magazine.