In preparation for the caucus, the Iowa Democratic Party wanted to update its reporting infrastructure, moving away from a system in which the state’s precincts would phone in results to the state party and introducing an app the precincts could use to simply upload the information. The party paid Shadow $60,000 over the past few months to develop an app called IowaReporterApp, according to financial disclosures. In principle, this is not a complicated application. It must send the results from 1,700 precincts to a central office for tabulation. The caucus runners had to take and upload a picture of their results, which were then supposed to be captured by the app.

Read: Who needs the Russians?

But something or somethings went wrong. Vice detailed failed attempts to log in to the app, and noted that very little testing could have been completed on the app, because of the short development period. In cases when precinct chairs were able to log in, according to CNN, the Shadow app struggled at the final step of the results-reporting process. A precinct chair told CNN that after the precinct chairs uploaded the photo, “the app showed different numbers than what they had submitted as captured in their screenshot.”

The Iowa Democratic Party appears to have confirmed that this is what went wrong. “While the app was recording data accurately, it was reporting out only partial data. We have determined that this was due to a coding issue in the reporting system,” the party’s chair, Troy Price, said in a statement this morning. “This issue was identified and fixed. The application’s reporting issue did not impact the ability of precinct chairs to report data accurately.”

To damp down fears about the integrity of the data, the Iowa Democratic Party has emphasized the existence of a paper trail, a key facet of election integrity. “Because of the required paper documentation, we have been able to verify that the data recorded in the app and used to calculate State Delegate Equivalents is valid and accurate,” Price said.

Over the past 20 years, small technology companies like Shadow have become an important piece of what it is to run for office. You need websites, digital advertising, and voter-data handling, as well as fundraising and voter outreach via text and email. While large campaigns can afford their own tech teams, most candidates and pieces of the party infrastructure rely on outside vendors, which supply them with software. Before this week, Shadow had highlighted only one client: the Hampden Township Democratic Club, in New Jersey.

Niemira, the CEO of Shadow, was the director of product for Clinton’s 2016 presidential campaign, working on voter-outreach tools. One staffer who worked closely with Niemira described him as “an exceptionally nice guy who knew what he was doing,” and told me that the email and text-messaging tools his team built worked well. (The staffer requested anonymity for privacy reasons.)