A web team that ships a bad change reverts it in minutes. A mobile team cannot. The build is on the customer's phone and stays there until they update. The only way to turn a feature off after release is to have built the switch before it.
Two Levers, Often Confused
A staged rollout controls who receives a new build. A feature flag controls what that build does once it is installed. They answer different questions, and a release plan that has only the first cannot switch off a single feature without halting everything else in the build.
The common tool is Firebase Remote Config, which its vendor describes as "a cloud service that lets you change the behavior and appearance of your client app or server without requiring users to download an app update" (Firebase).
The Wiring the Vendor Warns Against
Most teams fetch new settings when the app opens and apply them immediately. The vendor's own guidance on that approach is blunt: "Avoid this approach in any situation where your UI could change noticeably while users are using it" (Firebase).
Consider what that means in a checkout. A customer is entering payment details and the screen changes underneath them. The safer pattern, which the same guide calls effective, is to "load new configuration values to activate on your app's next startup". Each session sees one consistent app. Only a true emergency switch should act mid-session.
The Bill Arrives Later
Every flag is a second version of the product that has to keep working. A flag that is never removed is permanent complexity, and nobody budgets for it. Our earlier article quoted industry figures for this. They had no source and we removed them. What we can say from practice is that flags need an owner and a removal date on the day they are created, and an automated check that fails when the date passes.
What to Ask Your Team
- Which features in the next release can be switched off without a new build?
- Can a setting change a screen while a customer is using it?
- How many flags do we have, and how many have a removal date?
- Who is told when a flag is overdue?
-Rocky
#ReleaseManagement #FeatureFlags #RiskManagement #EngineeringDreams #StrategiaX
Originally published on ANDROID-ARCHITECT, the Android engineering blog of Strategia-X, with the implementation.