A Former Googler Explains Why the U.K.’s Contact Tracing App Was a Disaster
And what everyone else can learn from it
On June 18, the British government suddenly abandoned development of its contact tracing app, which was intended to tell people if they had come into close proximity with someone who tested positive for Covid-19. It worked 4% of the time.
That completely unacceptable result came from poor decisions based on hubris and a lack of technical understanding. The British government was aiming to build a “world-beating” app without the knowledge of the foundations that the technology was being built on.
From the perspective of a former Google product manager, the U.K.’s failure to build contact tracing apps offers many lessons and examples of common mistakes in product development.
How did we get here?
On April 10, Google and Apple announced they would work together to develop a framework that would help contact tracing apps work smoothly on their operating systems. They proposed using Bluetooth technology: Your smartphone would exchange anonymous keys with other devices nearby, and it would keep those keys for 14 days. If you receive a positive test and declare your status in the app, every other owner of a device that has your key will then get notified that they have been exposed. The idea behind the keys is to avoid gathering sensitive information about a user’s identity and location — your phone can be alerted that you crossed paths with someone who tested positive without gathering information about who that person is or where you encountered them.
Two days after Apple and Google’s announcement, the U.K. said that its National Health Service (NHS) was “working closely with the world’s leading tech companies” to develop a contact tracing app. Soon after, the U.K.’s NHS opted for an approach dependent on a central database that could process testing result information and reidentify individuals who had come into close contact with someone who was Covid-19 positive. Although advocates had raised privacy concerns over this approach, health services said they could use this data to identify virus hot spots, anticipate spread, and uncover other risk factors.