6.1.2. RQ2
“What are the commonalities in the evolution policies for web APIs?”. In a survey on “Web API Evolution Pains” the authors concluded that “there’s nothing even resembling industry standards, just best practices that everyone finds a way around”. When it comes to evolution policies, this seems to be true as well. Google and Twitter make use of versioning and give ample periods of time (∼2 years and 6 months respectively) for the client developers to migrate. Facebook opts for not providing versioning altogether and pushes breaking changes every three months. Lastly, Netflix with already two existing versions continues to maintain both versions simultaneously. Twitter also stands out for the “blackout tests” which serve as warnings for developers that eventually the old web API version will be shutdown