LaunchDarkly Ratelimit Demo

Example Express app that shows how to use LaunchDarkly's node SDK as a rate limit provider for express-rate-limit.

This shows how LaunchDarkly operational feature flags can be used for service protection. Here - we allow detailed targeting at the user or customer account level.

In order to make this example production-ready, the following changes must be made:

1. Rate limiting should be unique per endpoint, or class of endpoints
2. Replace the in-memory store with a redis store
3. Consider rate limiting un-authenticated requests as well

Accompanying LaunchDarkly Setup

1. Create a single feature flag called rate-limiting
2. Create the following rules

Name	Count
Suspended	1
Low	3
High	10
Unlimited	-1

3. Add user targeting so alice is served the Suspended variation
4. Add user targeting so max is served the Unlimited variation
5. Add rule targeting so customerAccountId=2 is served the High variation