Democratizing online controlled experiments at Booking.com

TL;DR

Booking.com has developed a comprehensive infrastructure and organizational practices over ten years to democratize online controlled experiments, enabling widespread participation and trust in data-driven decision making.

Contribution

The paper details the design and implementation of a scalable, transparent experimentation infrastructure that promotes democratization and decentralization within a large organization.

Findings

Successful democratization of experimentation at Booking.com

High trust and reliability in experiment data pipelines

Widespread organizational engagement in data-driven decisions

Abstract

There is an extensive literature about online controlled experiments, both on the statistical methods available to analyze experiment results as well as on the infrastructure built by several large scale Internet companies but also on the organizational challenges of embracing online experiments to inform product development. At Booking.com we have been conducting evidenced based product development using online experiments for more than ten years. Our methods and infrastructure were designed from their inception to reflect Booking.com culture, that is, with democratization and decentralization of experimentation and decision making in mind. In this paper we explain how building a central repository of successes and failures to allow for knowledge sharing, having a generic and extensible code library which enforces a loose coupling between experimentation and business logic, monitoring closely and transparently the quality and the reliability of the data gathering pipelines to build trust in the experimentation infrastructure, and putting in place safeguards to enable anyone to have end to end ownership of their experiments have allowed such a large organization as Booking.com to truly and successfully democratize experimentation.