AT&T Develops a New Way to Work, with a Cloud-First Approach in Azure

AT&T had reached a point where the complexity of its IT environment was hampering its ability to respond quickly to new customer needs and market opportunities.

It decided to move to a cloud-first approach in Azure, migrating approximately a third of its 7,500 applications to the cloud and retiring another third.

This reduced its on-premises infrastructure requirements by about 70 percent and reduced IT costs by about 30 percent. Moving development to Azure saves developers weeks of setup time, enabling much quicker product and services development cycles.

Their ‘Cloud First’ strategy meant a wholesale embrace of the Cloud for all enterprise IT where possible, such as also moving away from custom development wherever possible and moving more of their business-critical applications into SaaS solutions, working with partners building best-of-breed products.

Legacy Modernization

Since patenting the first telephone in 1876, AT&T has led the world in connecting people to one another and to the organizations and resources they need to thrive.

Over those 147 years, the company had accumulated about 7,500 applications and a complex infrastructure of mainframes and mid-range servers distributed over 34 data centers worldwide. By 2019, some of that infrastructure, and a lot of the homegrown software embedded in those applications, was decades old, which created a complicated IT environment.

The AT&T technology team spent about six months analyzing which of its 7,500 applications should be retired, retained, or combined with functions in other applications, and which should move to the cloud. When the analysis was complete, they retired about a third of the applications, designated about a third for the cloud, and identified about a third of the apps to stay in a scaled-down footprint of six data centers.

The technology team further divided those applications designated for the cloud into apps that required source-code changes before they could move to the cloud—the team called this “the modernization migration”—and apps that required few or no source-code changes—called “the optimization migration.”

For the first group, the migration team made the fewest source-code changes possible, such as moving a VMware-hosted app that used MySQL to Azure SQL Managed Instance before moving it to the cloud. For the second group, the migration team optimized the footprint, through actions such as replacing logging tools with the Log Analytics tool in Azure Monitor, before moving it to the cloud.

By March 2023, AT&T was approximately 90 percent finished with retiring applications and moving applications to the cloud. The company also has a strategic alliance with Microsoft to move its 5G mobile network to Azure. When the move is complete, all AT&T mobile network traffic will be managed with Microsoft Azure technologies.

Establishing a cloud-first strategy saves AT&T development time and hardware costs and significantly reduces data center costs related to energy, real estate, networking, and administration. By the end of 2022, the company had shut down 10 of its 34 data centers and will continue to close an additional 18 data centers.

Accelerating Digital Innovation

Moving development to Azure enabling much quicker product and services development cycles, saving developers weeks of set up time.

“In the past, a developer may have had to spend weeks or even months procuring the infrastructure they needed to test and deploy an application. Now they can execute those tasks in minutes,” says Summers.

This allows AT&T to accelerate new product introductions, while reducing the risk and cost of trying new ideas. If a new idea fails, developers can shut down the development environment without having to tear down and redeploy servers.

“In this new Azure environment, the infrastructure is available to developers immediately along with a set of services and capabilities that come along with Azure, which makes it a lot easier for people to innovate,” says Summers. “We also see savings in terms of development efficiency.”

Digital Skills

Another benefit of moving a large share of its applications to Azure and emphasizing cloud-first development is increased employee satisfaction. Upskilling the workforce with cloud tools helps them work more efficiently and effectively so they have more time to develop new ideas.

“We went from having a handful of Azure cloud certifications to being one of the most cloud-certified Azure clients in the world—and in a relatively quick time frame for a company of our size,” says Legg. “Our migration to Azure really changed the nature of the skills of our workforce.”

Those new skills include using AI to automate a variety of tasks, such as computer configuration management to identify potential problems or add capacity. The technology team is also training a tenant of ChatGPT on Azure to help employees complete HR tasks. And they’re exploring the potential of using ChatGPT for legacy code conversions to migrate from one computer language to another.

Read more in the full case study.