With Heathcare.gov, that is. This is from the Washington Post:
About a month before the exchange opened, this testing group urged agency officials not to launch it nationwide because it was still riddled with problems, according to an insurance IT executive who was close to the rollout…
Some key testing of the system did not take place until the week before launch, according to this person. As late as Sept. 26, there had been no tests to determine whether a consumer could complete the process from beginning to end: create an account, determine eligibility for federal subsidies and sign up for a health insurance plan, according to two sources familiar with the project.
People working on the project knew that Oct. 1 was set in stone as a launch date. “We named it the tyranny of the October 1 date,” said a person close to the project.