Public cloud provider Skytap has closed a $45 million Series E funding round this week, led by Goldman Sachs Private Capital Investing.

Skytap has carved a niche for itself in the enterprise with its Skytap Cloud service which mirrors the on-premises data center environment so customers can move traditional applications unchanged. Once their core applications are in the cloud, customers “modernize the technology and processes used to create and enhance their applications over time.” Nearly 60 percent of its revenue now comes from large enterprises.

The company said its approach helps to remove barriers to cloud migration and accelerates the timeline because the work to modernize the applications happens once they are already in the cloud.

Skytap also provides professional services around enterprise cloud migration, and is the only infrastructure as a service provider that supports IBM’s AIX operating system, in addition to Windows and Linux.

This investment comes as Skytap is seeing strong customer momentum, with existing customer upgrades up 130 percent YoY in Q2 2017 and average revenue per customer up 60 percent in the same period.

As part of the investment, Hillel Moerman, managing director of Goldman Sachs Private Capital Investing will join Skytap’s board of directors.

“Modernizing applications through cloud is fundamental to competing in the digital economy, but standard clouds can’t support the majority of applications at the heart of enterprises,” said Thor Culverhouse, CEO, Skytap. “Skytap Cloud lowers the barriers to modernizing these traditional applications by accelerating cloud migration to provide true scalability, self-service, and dynamic management. This, in turn, streamlines development and speeds innovation. Our unique approach sets us apart in the cloud and gives us the opportunity to enable greater cloud adoption for traditional enterprise applications.”

“We believe that Skytap is well-positioned to address the large and growing demand for helping enterprises modernize business-critical applications in order to harness the opportunity and full value of the public cloud,” said Moerman. “This untapped market is exciting, and we are pleased to support Skytap during this time of growth.”