Dumping mainframes for cloud can be a costly mistake

A certain Fortune 500 financial institution decided to fully embrace the cloud. Executive memos indicated that all their new initiatives would be “cloud-first.” Teams were encouraged to re-architect everything, including mission-critical transaction processing that had thrived for decades on robust mainframes. The company’s mainframe team, a group of highly skilled professionals, raised concerns. They believed the cloud wasn’t suited for certain high-throughput, low-latency workloads central to their business. However, in the exciting early days of cloud computing, those concerns went unaddressed.

Cracks began to appear a year into the migration. Cloud costs skyrocketed. Performance suffered. Customers complained about slow service during peak hours. The company had to call back its mainframe engineers and roll key workloads back onto the mainframe—this time integrating them more thoughtfully with new cloud-native services. Only then did resilience and customer satisfaction return.

The lesson? Never dismiss a proven technology (or the experts who manage it) just because a new one is more exciting.

Mainframes are still core components, not relics

Despite industry hype, mainframes are not going anywhere. They quietly support the backbone of our largest banks, governments, and insurance companies. Their reliability, security, and capacity for massive transactions give mainframes an advantage that most public cloud platforms simply can’t match for certain workloads.

Big players like IBM and Broadcom understand this well. They continue to invest in mainframe modernization—think APIs, containerization, and cloud integration features. Mainframes aren’t just legacy; they’re evolving. The people who keep these systems running aren’t museum curators—they’re essential to smooth operations and safety, especially for enterprises with decades of institutional knowledge embedded in these platforms.

Unfortunately, in many organizations the cloud is seen as the solution to every problem. This oversimplification positions mainframes and their operators as old-fashioned—a risky mindset for any business with real-time processing demands or compliance requirements that cloud alone can’t meet.

Hybrid excellence: Mainframes and cloud together

The question isn’t whether the cloud is important. It absolutely is. The cloud unlocks agility and scalability that businesses could not have dreamed of 20 years ago. However, there’s a deeper truth: Not every workload belongs in the cloud, and not every system on a mainframe should remain there forever. Strategic organizations ask deeper questions: Which environment provides the best outcome for each task? Where are our strengths, and how can we combine them for improved business results?

Forward-thinking IT leaders are demonstrating that hybrid IT is the future. Mainframes are now being made “first-class cloud citizens,” participating directly in cloud-driven devops workflows and data exchanges. IBM and Broadcom are enhancing mainframe integration, building bridges with public and private clouds. This means mainframe and cloud professionals must collaborate closely, each contributing their expertise and insight.

The enterprises that thrive in this new era are those that eliminate silos. They capitalize on mainframes for their strengths (transactional integrity, security, scale) while employing the cloud where it excels (agility, global scale, rapid innovation). Only by recognizing the unique benefits of each environment can companies unlock true innovation.

A culture of tech respect and open-mindedness

At the core of this conversation is culture. An innovative IT organization doesn’t pursue technology for its own sake. Instead, it encourages teams to be open-minded, pragmatic, and collaborative. Mainframe engineers have a seat at the architecture table alongside cloud architects, data scientists, and developers. When there’s mutual respect, great ideas flourish. When legacy teams are sidelined, valuable institutional knowledge and operational stability are jeopardized.

A cloud-first mantra must be replaced by a philosophy of “we choose the right tool for the job.” The financial institution in our opening story learned this the hard way. They had to overcome their bias and reconnect with their mainframe experts to avoid further costly missteps.

It’s time to retire the “legacy versus modern” conflict and recognize that any technology’s true value lies in how effectively it serves business goals. Mainframes are part of a hybrid future, evolving alongside the cloud rather than being replaced by it. Mainframe engineers should be acknowledged as key partners in the digital landscape.

Digital transformation isn’t just about technology—it’s about people and perspective. The strongest enterprise cultures recognize and embrace the value of every platform and professional, evaluating each decision based on merit rather than trend. By cultivating an inclusive technology culture that values mainframes, clouds, and the people who excel at either one, enterprises will position themselves for lasting success.