WASHINGTON — Before cost-cutting became fashionable in Washington, Vivek Kundra, the White House’s chief information officer, was working to shrink the federal government’s enormous budget for information technology.

But even as Mr. Kundra returns to academia after a two-and-a-half-year run, his vision for a leaner and more Internet-centric future for government is being met with caution by at least a few of the technology chiefs at the federal agencies that now have to carry it out.

That is because Mr. Kundra’s vision hinges on “cloud computing,” in which an agency’s computer programs (like e-mail) and data (like e-mail messages) are stored by private contractors and delivered to government employees as services over the Internet.

Contractors like Amazon, Google and Lockheed Martin market their cloud services as a way for private companies and government agencies to avoid having to build and manage costly new data centers as they add computing capabilities.