The bug spread through Twitters’ systems in a cascading effect, leading to a drop in service for its 150 million-plus users.
Vice President of Engineering Mazen Rawashdeh said in a blog post said that the loss of service “wasn’t due to a hack or our new office or Euro 2012 or GIF avatars, as some have speculated.”
“One of the characteristics of such a bug is that it can have a significant impact on all users, worldwide, which was the case [Thursday]. As soon as we discovered it, we took corrective actions, which included rolling back to a previous stable version of Twitter.”
Although its status blog at one point on Thursday said that the outage had been resolved, the webpage went down for a second time.
“The issue is on-going and our engineers are working to resolve it,” the status blog said.
Ray Wang, the CEO Constellation Research said that Twitter is building out its infrastructure to accommodate more users — as many as a billion, he said — and that something may have gone wrong.
“It’s not like it’s easy to do. They’re massively leveraged in terms of infrastructure,” he said on Thursday.
The outage is the first major service disruption since early May, according to the status blog.