Quality tutoring can be one of the building blocks in the bridges over many of the various "divides" - digital, economic, social and educational. Appalling recent statistics have shown that only 7% of South Africa's first year university students have sufficient mathematics knowledge and background to cope with university work. C³TO (Chatter Call Centre/Tutoring Online) is an architecture which facilitates mobile tutoring by linking primary and secondary school pupils to volunteer tutors from local South African universities to assist with mathematics homework. Pupils use chat software on their cell phones (with the majority using the Mxit instant messaging system) to discuss their mathematics homework with the volunteer tutors. The first implementation of such tutoring system yielded a much higher demand than was expected. This paper specifically reports on the scalability issues that were considered when designing the C³TO architecture. It argues for design interventions at three different levels and presents the current design accordingly.