[DVXPL26] From code to control: master deployments with Feature Flagging and OpenFeature

Shipping code is good. Shipping a new feature without breaking the rest of the system is even better!

Every release today brings the risk of regressions or bad interactions between existing and new functionality. And what about deploying to only a subset of users? That’s even trickier.

Feature flagging decouples code deployment from feature activation, allowing you to turn blocks on or off at runtime without redeploying.

Fortunately, this practice has been growing with open‑source tools and solid engineering habits. However, beyond simple if‑then‑else, most available solutions are proprietary, heavy or costly to set up.

OpenFeature, a CNCF project, offers an open specification for unified feature flagging, usable both server‑ and client‑side regardless of the backing store.

In this workshop we’ll add a new feature to an existing Java/Angular application and drive its activation through feature flags. Along the way we’ll cover key topics: error handling, A/B testing, progressive rollouts, targeting and observability.

By the end, you’ll know how to deliver faster, safer and with confidence.

Transcript

1. #DevoxxPL From code to control: master deployments with Feature Flagging and OpenFeature
2. Alexandre Touret Principal Software Architect 2 @touret.info blog.touret.info alexandre@piaille.fr alexandre-touret
3. Prerequisites 3 github.com
4. The Workshop 4 https://blog.touret.info/feature-flag-workshop/ https://github.com/alexandre-touret/feature-flag-workshop
5. What is Feature Flagging? 5
6. What is Feature-Flagging? Feature flagging is a software engineering technique that allows teams to turn functionality on or off at runtime without deploying new code. 6
7. Deployment vs Release 7 Deployment (Technical) • Pushing code Release (Business) • Choosing when a feature is active
8. Feature-Flagging vs Feature-Flipping 8 Feature Flipping Simple binary switch ON/OFF Feature Flagging More dynamic system
9. What about OpenFeature? • OpenFeature is an open specification sponsored by the CNCF that provides a vendor- agnostic, community-driven API for feature flagging. 9 https://openfeature.dev
10. The platform 10
11. Music Store 11
12. Thanks QQ 12 Alexandre Touret @touret.info blog.touret.info alexandre@piaille.fr alexandre-touret