How does it work?
Is it really A/B testing?
Technically, Birdy uses a method called "switchback testing". Instead of bucketing a profile visitor to experiment A or B, Birdy alternates between "treatment" and "control" periodically. In other words, Birdy buckets groups of profile visitors over time, rather than individual profile visitors. This approach of split testing has initially been popularized by DoorDash.
In many ways, switchback testing is exactly like A/B testing, but instead of randomizing based on something like deliveries, we randomize based on time-region units. —DoorDash