Managing Feature Flags

Chapter 4. From Continuous Delivery to Continuous Experimentation

In the introduction of this book, we touched upon the convergence of continuous delivery (CD) and experimentation driving “lean product development,” with feature flags being the foundational element powering this convergence.

Let’s explore the trends and practices that are driving this convergence.

CD became a well-defined strategy among forward-thinking engineering teams, and stemmed from the need for businesses to rapidly iterate on ideas. At the same time, product management teams were adopting lean product development concepts, such as customer feedback loops and A/B testing. They were motivated by a simple problem: up to 90% of the ideas they took to market failed to make a difference to the business. Given this glaring statistic, the only way to be an effective product management organization was to iterate fast and to let customer feedback inform investment decisions in ideas.

Common elements began to emerge, connecting both these trends in day-to-day software development and delivery. These elements included the need for rapid iteration, safe rollouts through gradual exposure of features, and telemetry to measure the impact of these features on customer experience. The resulting outcome is that modern product development teams are beginning to treat CD and experimentation (i.e., a more generic term for A/B testing) as two sides of the same coin. Core to both of these practices is the foundational technology ...