[6] She began her career in August 2004, at Unilever, the European consumer products conglomerate, working as the Assistant Regional Brand Manager in the laundry division, based in Durban, South Africa.

[6] In February 2006 she was hired by Safaricom Limited as the manager responsible for the company's pre-pay product, working in that capacity until November 2007, when she was promoted to the rank of Head of Retail, in which position she served until August 2009.

[7][8] In April 2018, Sylvia Mulinge was named the chief executive officer-designate at Vodacom Tanzania, replacing Ian Ferrao.

[9] In September 2018, Vodacom Tanzania enounced that the Tanzanian authorities had declined to issue Sylvia Mulinge with a working permit.

[10][11] Effective 1 October 2018 she was reassigned as the director of special projects at Safaricom, reporting directly to the company CEO.