Health and Human Services (HHS) Secretary Kathleen Sebelius had three-and-a-half years to build the Obamacare exchanges. Now, GOP House members in charge of oversight want answers as to how the online system that cost taxpayers over half-a-billion dollars has failed on such a grand scale.

On Thursday, House GOP members of the Committee on Energy and Commerce sent a letter to Sebelius requesting an oversight briefing to occur no later than October 16th. The letter says Sebelius’s staff told lawmakers that the Obamacare exchanges were “proceeding on schedule and did not identify any problems like the ones now being experienced on HealthCare.gov.” 

Technology experts have panned the federal government’s Obamacare website, which handles 36 state exchanges. Anti-virus software creator John McAfee says the Obamacare website is a “hacker’s wet dream.” And numerous others have rejected the Obama Administration’s excuse that heavy traffic caused system malfunctions.

“Any modern Web company would be well prepared for a launchof this scale,” RackSpace chief technology officer John Engates told the Washington Post. “We’re not talking about hundreds of millions of peopleand we’re not talking about complex transactions.”

In an interview with CBS News, online database programmer Luke Chung said that despite personally supporting Obamacare, he believes the government’s website is an embarrassing failure.

“It looks like nobody tested it,” said Chung. “It’s not even ready for beta testing for my book. I would be ashamed and embarrassed if my organization delivered something like that.”

On Saturday, Politico reporters Brett Norman and Jason Millman warned that Obamacare’s technical woes are far from over. “The glitch-plagued Obamacare rollout might be just the beginning: A series of potential technology problems could thwart the Obama administration’s goal of getting 7 million people enrolled in the new exchanges by the end of March,” reported Norman and Millman.

Tech expert Dan Schuyler helped build the Utah Obamacare exchange. He told Politico that if HHS does not fix the federal healthcare.gov website within three or four weeks, “those at the back of the line will not have coverage.”

Last week, Speaker John Boehner blasted the Obamacare tech debacle. 

“How can we tax people for not buying a product from a website that doesn’t work?” asked Boehner. 

And now, Sebelius’s longtime friend and fellow Kansan, Sen. Pat Roberts(R-KS), has become the first to call for the embattled HHSsecretary’s resignation.

Obamacare, which became law three-and-a-half years ago, will cost taxpayers $2.6 trillion over the next 10 years.