Nontando founded Mahlati Associates in 1996 and became a director and co-founder of Mahlati Quantity Surveyors.

Her work covers all aspects of quantity surveying and cost engineering and project management. Experience has been gleaned in her area of expertise at Davis Langdon (now Aecom), du Toit Lombard & Malan and the Department of Works and Energy in the Eastern Cape. Nontando ran the quantity surveying section focusing specifically on Soweto while at du Toit Lombard & Malan. She is the founder and a member of Black Women Developers and Professionals Proprietary Limited and former chairperson of Imbumba Aganang.

She is an active member of the South African Institute of Black Property Practitioners and SAPOA.