Prompt Library › ⚙️ Technical › Feature Flag System Designer
GPT-4o ⚙️ Technical Intermediate

Feature Flag System Designer

Design a feature flag architecture that supports gradual rollouts, A/B testing, and safe deployments for your stack.

👁 1 views ⎘ 0 copies ♥ 0 likes

The Prompt

# Feature Flag System Designer

You are a platform engineer who has built feature flag systems at scale. Design a feature flag architecture for the following use case.

## Use Case

Application type: [WEB APP / MOBILE APP / API]

Team size: [NUMBER OF DEVELOPERS]

Use cases: [gradual rollout / A/B testing / kill switch / beta access / trunk-based development]

Current stack: [LANGUAGE AND FRAMEWORK]

Scale: [APPROXIMATE NUMBER OF USERS AND REQUESTS PER DAY]

## Design Deliverables

**Flag data model** — Schema for storing flags, rules, and targeting criteria.

**Evaluation logic** — How flags are resolved for a given user in real time.

**SDK interface** — The API that application code uses to check a flag (with code example).

**Rollout strategy** — How to graduate a feature from 0% to 100% of users safely.

**Targeting rules** — How to target specific users, cohorts, or environments.

**Stale flag cleanup** — Process for identifying and removing shipped or abandoned flags.

Recommend whether to build or buy, with reasoning for this team size and scale.

📝 Fill in the blanks

Replace these placeholders with your own content:

[WEB APP / MOBILE APP / API]
[NUMBER OF DEVELOPERS]
[gradual rollout / A/B testing / kill switch / beta access / trunk-based development]
[LANGUAGE AND FRAMEWORK]
[APPROXIMATE NUMBER OF USERS AND REQUESTS PER DAY]

How to use this prompt

1
Copy the prompt

Click "Copy Prompt" above to copy the full prompt text to your clipboard.

2
Replace the placeholders

Swap out anything in [BRACKETS] with your specific details.

3
Paste into GPT-4o

Open your preferred AI assistant and paste the prompt to get started.