Feature Flag Journey Enables Vodafone to Enhance Digital Experiences

Vodafone is a leading technology communication company that serves more than 18 million mobile and fixed-line customers in the United Kingdom. Headquartered in Newbury, Vodafone plansto grow significantly to support its expanding digital services portfolio. By 2025, the company expects over 50% of all Vodafone employees will work in software engineering. Vodafone has been on a journey over the past several years to build world-class software engineering capabilities, making significant progress in modernizing its development processes. Vodafone organizes its developers into feature teams, of which there are currently 40. Each team consists of front-end and back end developers dedicated to a product vertical. The teams have an automated pipeline and use ScaledAgile Framework (SAFe) with three-month program increments. As part of this modernization,Vodafone set itself the goal of achieving 100 deployments a day, in which the company aspired to reach a point where software development teams could safely and securely deploy as frequently as they wanted. However,Vodafone's software development teams were performing "big bang" releases once per quarter only four years prior. Accelerating software delivery required a significant cultural and behavior shift. Previously, deployment and release were the same for most software development teams at Vodafone. But leadership recognized the need to decouple deployment and release to achieve continuous deployment. Decoupling software deployments from releases permitted the teams to deploy updates more frequently and gradually release individual features instead of rolling them out all at once.

Vodafone recognized that feature flags could enable this decoupling and decided to create its own feature flags by adding boolean flags to the source code and usingenvironment variables to turn the features on and off. However, this roll-yourownapproach to feature flagsrequired a new build and release for every change, which wasteddevelopmenttime and proved difficult to manage. It was challenging to releasesmaller changes in isolation, resulting in larger "flip" releases, where several changes were bundled together and then flipped from blue to green. These larger releaseswere timeconsuming, problematic, and risky because if a single change embedded in the release was broken, the rest would need to be backed out. It could take developers hours toturn off one of these homegrownflagswhile negatively impacting customers. Once it became clear that Vodafoneneeded a full-fledgedsolution, the company chose theLaunchDarkly Feature Management Platformto provide the speed, scale, and flexibility required to release more frequently with confidence.