Microsoft pulled off an upset, beating Amazon for a defense contract valued as high as $10 billion.

According to a statement by the U.S. Department of Defense, Microsoft emerged the winner of the JEDI Cloud contract. The win is a major step in Microsoft’s attempts to take on Amazon, widely regarded as the industry leader. It’s also a testament to how far the Azure platform has matured to become a viable competitor to AWS.

“The JEDI Cloud contract will provide enterprise level, commercial Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) to support Department of Defense business and mission operations. Work performance will take place at the awardee’s place of performance. Fiscal 2020 operations and maintenance funds in the amount of $1,000,000 are being obligated on a task order against this award to cover the minimum guarantee. The expected completion date is Oct. 24, 2029, if all options are exercised.”

Since CEO Satya Nadella took the reins from Steve Ballmer, he has increased the company’s focus on cloud computing and cross-platform interoperability, a strategy that has paid off as Microsoft navigates a more mobile, cloud-based industry. These kind of gains will likely lead more companies to take note of Microsoft’s offerings, further putting pressure on Amazon.