Every second, thousands of Kenyans send and receive money, pay for goods, access loans, or settle bills through M-PESA.

It’s so woven into daily life that for most people, it’s as natural as breathing.

But behind the familiar green logo is a massive, constantly evolving tech operation that ensures transactions happen seamlessly.

The technology behind M-PESA is essentially an application – the software – and databases where transactions are processed after being initiated by the application. The M-PESA system has more than 700 servers that make it possible to process requests for transactions, check whether the user has the balance needed and whether the receiver is available to receive the request and to send the necessary notifications as a text message.

Felix Rop, Safaricom’s Head of Financial Services Technology, says the scale is staggering and still growing.

“What we have today is a system that runs in three environments: a production environment, a disaster recovery environment and another disaster recovery environment in the sense that if we lose one environment, we are able to switch traffic from one environment seamlessly to another environment,” said Rop.

The production environment is where the software that runs M-PESA is live, enabling users to make transactions. The disaster recovery environments are essentially the sites that enable the system to keep running in the event of a failure.

With M-PESA, said Rop, the traffic is switched over within four minutes in case of a failure in one environment, with everything done to ensure that users’ M-PESA balances remain the same. With the data centers in different locations, what is known in technology parlance as geo-redundancy, the system continues running if one location goes down.

The M-PESA team’s target now is to increase the capacity of the system by adding servers to increase the number of transactions it can handle per second from the current 4,000.

For context, the capacity was 616 transactions per second when the M-PESA system was brought to Kenya in 2015.

“If you recall, in 2015, 2016, and 2017, we used to have a lot of notifications every other weekend that we are upgrading the system and we would bring down the system to be able to upgrade,” said Rop.

These notifications have reduced over time but the system continues to be upgraded every two months. Still, there is more to do.

“By next year, we will be doing over 6,000 to 8,000 transactions per second. That’s not just a number, it’s an engineering challenge,” he noted.

M-PESA isn’t just about speed, it’s about trust. With billions of shillings moving through the system every day, fraud prevention is a critical part of the operation.

Behind the scenes, teams are constantly monitoring the system health using Artificial intelligence (AI) tools and in network operations centers that run 24/7 to track every transaction, every system alert, and every performance metric in real time.

“The AI models look for unusual patterns, like someone trying to withdraw more than they usually do or making many transactions within a short span of time. When that happens, the system can flag or even freeze suspicious activity instantly,” Rop said.

For the team, this provides a backbone of reliability.

To manage transaction volume for today and tomorrow, Rop points out that M-PESA’s infrastructure has been designed with elasticity in mind.

“We are always building for capacity we have not yet reached. When we do load testing, we push the systems to handle even double the current transaction volume,” he said.

That foresight is what allows M-PESA to scale without hiccups, even during peak moments like holiday shopping sprees or special promotions.

From encryption protocols to strict access controls, the team behind M-PESA ensures that security is baked into every layer of M-PESA’s architecture as it is not something you add later; it has to be part of the foundation.

Even upgrades and feature rollouts follow rigorous protocols. “Before a single update goes live, it’s tested in staging environments then in a pilot program before we push it to all customers,” Rop said.

What started as a money transfer service has now grown into a lifestyle enabler. With M-PESA now integrating with banking, e-commerce, savings, lending, and even insurance, it’s become a platform where you can do almost everything without ever leaving your phone.

It is for this reason that this expansion requires M-PESA’s tech backbone to be even more resilient.

For most Kenyans, M-PESA is not just convenient, it is essential. A single hour of downtime could disrupt markets, stall payments for farmers, or delay salaries for thousands.

“We treat M-PESA like a living system. It needs constant care, constant improvement,” Rop said.

Keeping M-PESA running is a continuous journey. It’s about anticipating problems before they happen, and making sure the customer never feels the weight of the work happening behind the scenes.

If you’re reading this while sending money to a friend or paying for lunch via M-PESA, it’s worth remembering there’s an entire invisible network and a team of people making sure that transaction happens instantly, securely, and without fail.