The app that the Iowa Democratic Party commissioned to tabulate and report results from the caucuses on Monday was not properly tested - The New York Times

https://www.nytimes.com/2020/02/03/us/politics/iowa-caucus-app.html

“The consensus of all experts who have been thinking about this is unequivocal,” Mr. Blaze added. “Internet and mobile voting should not be used at this time in civil elections.” Any technology, he said, should be tested and retested by the broader cybersecurity community before being publicly introduced, to test for anything ranging from a small bug to a major vulnerability. “I think the most important rule of thumb in introducing technology into voting is be extremely conservative,” he said