There is a corner office on the third floor of a converted warehouse in Diepkloof that has the best view of Soweto that money can currently rent. From the window you can see the Orlando cooling towers — decommissioned, painted, now a zip-line attraction — and, on a clear day, the Hillbrow Tower in the distance. The office belongs to Nkosi Mahlangu, 31, who is building a logistics platform that matches informal traders with last-mile delivery capacity across the country's seven largest townships. His company, Ntaba, has raised $4.1 million in seed funding from a London-based VC firm that heard about it from another founder in Nairobi. "They found me on LinkedIn," he says, with a shrug that suggests this still surprises him. "I had not thought of us as internationally interesting yet."
Mahlangu is one of four founders operating from what has come to be called, with varying degrees of irony, the Soweto Stack — a loose constellation of Joburg-based technology companies that are building products specifically for the African market and attracting attention they did not solicit. The term was coined by Sizwe Moyo, whose fintech startup Imali enables informal-sector workers to save and borrow in increments small enough to fit inside a daily wage. Moyo, 28, grew up in Meadowlands and studied computer science at UJ. He launched Imali in 2023 with R150,000 from a family member and a side project he sold for parts. Today the platform has 340,000 active users and processes roughly R22 million in transactions each month.
The third member of the informal cohort is Thandi Nkosi, who is doing something that has repeatedly been described to her as impossible: building a primary healthcare scheduling and record-keeping system for community health workers operating in areas with unreliable internet connectivity. Her company, Phakamisa Health, uses a combination of USSD — the two-decade-old mobile technology that works on any phone without data — and a lightweight sync protocol that uploads patient records whenever a connection becomes available. "Every consultant told me to build for smartphones," she says, seated in a shared workspace in Jabulani. "I told them I was building for community health workers in Limpopo. They have feature phones. The problem is the problem."
Trust is infrastructure. In South Africa we just never built it properly for this part of the economy — and that gap is exactly where we're building.
Kagiso Sithole is the fourth founder, and his problem is one of the oldest in African business: trust. His company, Cheka, provides identity verification for the gig economy — not the formal gig economy of Uber and Mr D, but the informal one: the plumber who comes recommended by a neighbour, the domestic worker applying for her first household position, the freelance electrician trying to build a client base in a new suburb. Cheka uses a combination of home affairs database integration, peer references, and a portable reputation score that travels with the worker rather than residing with any single employer. "Trust is infrastructure," Sithole says. "In South Africa we just never built it properly for this part of the economy."
What unites these four companies is not their sector but their design constraint: they are all building for conditions — low bandwidth, low income, high friction — that first-world technology assumptions render invisible. The platforms coming out of Silicon Valley, even the ones positioning themselves as solutions for "emerging markets," are built first for a user with a recent iPhone, reliable broadband, and a credit card. The Soweto Stack founders build first for a user with a 2019 Android, intermittent 4G, and an informal income. The international attention they are now receiving is, in part, a recognition that this design constraint is not a limitation. It is a competitive advantage.
The attention has started to arrive in material form. Ntaba closed a Series A in February, led by the Cape Town office of a pan-African growth fund. Imali has been approached by two tier-one South African banks about a white-label partnership. Phakamisa Health was selected, in March, as one of twelve companies in the WHO's digital health accelerator cohort for sub-Saharan Africa. Cheka is in conversation with a government department about integrating its verification layer into the unemployment insurance system. "We didn't build for the world," Nkosi Mahlangu says, looking out at the cooling towers. "We built for here. It turns out here is a bigger market than we thought."
