Apple is looking to bolster its services backend with major expansions at existing data centers in Arizona and Nevada, including a $1 billion investment that doubles its commitment to a Reno Technology Park facility.

According to AppleInsider sources, construction of a previously planned "phase 2" addition to Apple's Mesa, Ariz., data center is well underway. Contractors are busy outfitting the facility with new equipment, while construction crews work to build out roads and supporting infrastructure surrounding the campus.

Apple is expected to further increase the size of its Arizona data center in the near future as part of a "phase 3" expansion, sources said. 

In 2015, Apple promised to invest $2 billion over ten years in a global command data center to be built at the site of the company's failed sapphire production project. That commitment was later raised to $2 billion over five years, with plans to set aside additional funding for 30 years. 

The upcoming phase 3 upgrades have not been disclosed publicly, but are thought to be part of the previously announced investment. 

Source: appleinsider