Feature Flags & Progressive Rollout

A feature flag lets a team deploy code without immediately turning it on for everyone — enabling it for internal users first, then a small percentage of real traffic, then everyone, with the ability to instantly turn it back off if something goes wrong, no redeploy required.

Decoupling deployment (the code is live on the server) from release (the feature is actually turned on for users) is the core idea — a bug in unreleased code can't affect anyone

A percentage-based rollout limits the blast radius of an unexpected bug to a small slice of traffic, and provides real production signal before a full launch

An instant kill switch (flipping the flag back off) is dramatically faster than a rollback-and-redeploy cycle when something goes wrong in production

Stale flags left in code long after a feature is fully launched (or fully abandoned) accumulate as technical debt and dead conditional branches — flag cleanup is a real, recurring maintenance task

Hands-on demo

Roll out a new checkout flow

Dial in a rollout percentage, simulate 10 users hitting the app, then imagine a bug appears — hit the kill switch.

Rollout 20%

Try it yourself

Try it yourself — run a scenario below, then flip this and replay it to see what changes.

Gradual Rollout of a New Checkout Flow

A redesigned checkout page ships to 5% of traffic before going to everyone.

Want this flow explained in detail as it plays?

app.flowground.dev/admin/flags

Feature flags

new-checkout-flow0%

Platform

Users

The code is live on the servers, but no real user sees it yet — the flag is fully off.

Selected hop

New checkout flow deployed behind a feature flag, set to 0% of traffic

Platform

The system operating the feature — flags, moderation, or infrastructure — for every user.

Platform

The system operating the feature — flags, moderation, or infrastructure — for every user.

What happens here

The code is live on the servers, but no real user sees it yet — the flag is fully off.