Why This Construction Tech Founder Started With Cement (Not Software)

Author

Owen Drury
July 02, 2025 • Estimated Reading Time: 14 minutes

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INDUSTRY INSIGHTS
Why This Construction Tech Founder Started With Cement (Not Software)

How Jumba built a 700+ hardware store network using WhatsApp, mobile money, and high-volume logistics

I recently posted a post on LinkedIn with a link to our episode with Kagure Wamunyu. This episode took us around 8 months to finally get on the calendar and boy am I glad we did!

We have never spoke to an African tech company before. And I’m glad Jumba was our first. What struck me were the major cultural differences one must consider when thinking about other continents. 

For example, Kagure was the country manager for Uber when it arrived in Kenya. 

As Uber's Kenya operations lead, she was watching a world-class product fail spectacularly. The ride-hailing giant had launched across Sub-Saharan Africa as a credit card-only product. 

In Kenya, it was dying a slow death.

The problem? Credit cards barely existed. 

In a country where over 60% of GDP flows through mobile money wallets tied to phone numbers, Uber was demanding plastic that locals didn't have or want.

"HQ in San Francisco was like, 'You guys are insisting on this mobile money thing, but you can go ahead, we will not fully build for you,'" Kagure recalls.

So she did something that would horrify any Silicon Valley product manager: She ran Uber on Excel spreadsheets. :O :O

Here's how it worked: Drivers would complete trips. Kagure's team would run scripts trying to reconcile payments on Excel. Then drivers would line up, one by one, to settle their mobile money accounts manually.

It was messy. It was manual. It was completely contrary to Uber's tech-first DNA.

It also made Kenya the first city in the world to roll out 100% cash payments on the Uber platform.

"Back then, we ran Uber on Excel sheets," she says, almost proudly. "As tough as it was and manual as it was, it really unlocked Nairobi."

That experience taught Kagure two lessons that would shape her entire approach to building construction tech in Africa:

  1. Great tech that works elsewhere can fail spectacularly if it doesn't fit the market

  2. Don't be afraid to run things manually while you prove the model

Today, Kagure is the founder of Jumba, a construction tech platform serving 700+ hardware stores across Kenya. But her success didn't come from following Silicon Valley playbooks—it came from breaking them.

TL;DR: Why Jumba Built a Cement Empire on WhatsApp

  • Silicon Valley playbooks failed Kagure Wamunyu, so she built her own.

  • Running Uber on Excel taught her to meet markets where they are—like Kenya’s WhatsApp-driven, mobile money-fueled economy.

  • Starting with cement justified building Kenya-wide logistics, letting Jumba serve 700+ hardware stores.

The lesson? In emerging markets, success means starting with volume, layering on tech later, and expanding along trade routes—not tech hubs.


The Market Reality That Changes Everything

When Kagure decided to become a real estate developer in Kenya (her "side hustle" while working in tech), she discovered something that would reshape her entire career:

In Kenya, people build homes rather than buy them.

Why? Mortgages cost 15% annually. So Kenyans get money, build a stage, stop, then continue when they get more money. 

This creates a massive network of hardware stores serving individual home builders and small developers—stores doing anywhere from $50,000 to millions in monthly revenue.

And here's the kicker: Manufacturing is centralized in major cities while development happens everywhere. The further you are from Nairobi, the harder it is to access construction materials affordably.

This isn't just a Kenya problem, it's the reality across emerging markets where traditional distribution models break down outside major metropolitan areas.


The High-Volume, Low-Margin Strategy That Built Jumba

Most construction tech companies start with high-margin, low-volume products. Kagure did the opposite, and there's brilliant logic behind it.

Jumba started with cement. 50kg bags, commoditized, high-volume, low-margin. Why?

"You've got to have the ability to move trucks into multiple areas of the country," Kagure explains. "The bulk products allow you to be able to move the truck because the transport component can pay for the load."

The strategy evolved methodically:

  • Phase 1: Cement (the foundation product everyone needs)

  • Phase 2: Steel and deformed bars (complementary, still bulk)

  • Phase 3: Wire products and nails (lighter, higher margin)

  • Phase 4: Finishes (where tech value proposition really shines)

Each phase builds on the logistics infrastructure of the previous one. By the time you get to tiles and finishes (where customers care about seeing options, comparing colors, and making aesthetic choices) you have the distribution network and customer relationships to make the tech play work.

The lesson for emerging markets: Start with what justifies the infrastructure, then layer on the high-value, tech-enabled products.


Building When Supporting Infrastructure Doesn't Exist

Here's what blew my mind: In developed markets, you'd use separate companies for logistics, warehousing, payment processing, and order management. In Kenya, Kagure had to build all of this herself.

"When you're building in Africa, you have to build for your own ecosystem," she says. "You're building multiple products. What would be different businesses in other markets, here you become it."

Jumba's "simple" B2B marketplace actually includes:

  • Order management system: customers send WhatsApp photos of handwritten quotes

  • AI quote reader: converts those photos to structured data

  • Logistics management: tracking trucks across the country

  • Mobile money integration: because 60% of Kenya's GDP runs on mobile wallets

  • Multi-manufacturer bundling: combining cement, steel, and nails in one delivery

What started as internal tools became their SaaS product, now being deployed to manufacturers who currently run everything on WhatsApp after their basic ERP systems.


The WhatsApp Economy (And What It Means for Sales)

Forget LinkedIn. 

In Kenya's B2B world, everything runs on WhatsApp and Facebook.

"If you ask me the best tech that ever happened in Africa, it's WhatsApp," Kagure says.

Orders get posted in WhatsApp groups with directors, forwarded to finance teams, and payment confirmations shared in group chats.

For customer acquisition, Jumba uses:

  • Facebook ads: where their customers are extremely active

  • TikTok: surprisingly big with middle-aged and older demographics for news and trends

  • Referral programs: relationship-based selling is critical

  • Boots on the ground: for new market entry, then pulled back to centralized sales

The broader lesson: Meet your customers where they actually are, not where you think they should be.


The Mobile Money Revolution

Here's a stat that should make everyone think: Over 60% of Kenya's GDP runs on mobile money. You buy groceries, pay for Uber, handle government services—all with your phone number and mobile wallet. No bank account required.

This isn't just convenient; it's transformative for construction. Jumba built auto-reconciliation for mobile money payments because that's how their customers actually transact.

For emerging markets: The financial infrastructure might be completely different from what you're used to. In Kenya, mobile money is more ubiquitous than credit cards ever were in the US.


Expansion Strategy: Following Trade Routes, Not Tech Hubs

Most people think: Start in Kenya, expand to Nigeria (the largest African market). Kagure thinks differently.

"The power is actually in not moving from Kenya to Nigeria. It's really thinking about who does Kenya trade with, what markets are similar to Kenya."

Her expansion strategy follows existing trade relationships:

  • East African Community: borderless trading bloc

  • Existing supply chains: goods to Uganda and Congo already come from Kenya

  • Natural distribution routes: don't create new infrastructure, follow existing paths

The insight: In emerging markets, expand along natural trade corridors rather than jumping to the biggest population centers.


What This Means for People Build In Construction Tech

Kagure's story isn't just about Africa. It's about building where traditional playbooks don't work. Whether you're entering rural markets, serving smaller contractors, or working with cash-heavy industries, the principles apply:

  1. Start with volume products that justify infrastructure, then layer on tech-enabled services

  2. Build end-to-end solutions when supporting services don't exist

  3. Meet customers on their preferred platforms, even if it's WhatsApp… controversial or what….

  4. Follow existing relationships and trade patterns, not just population centers

  5. Adapt payment and fulfillment to local reality, not your assumptions

Ultimately, when thinking about emerging markets, do not be afraid to go against the normal startup building playbook.

The global construction industry is worth $12 trillion annually. Most of that happens outside major metropolitan areas, in markets that look more like Kenya than Silicon Valley.

The question isn't whether there are opportunities in emerging markets. It's whether you're willing to build differently to capture them.

Watch the full episode with Kagure Wamunyu here👇👇👇

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