SDK Preflight Checklist

Audience: Developers who are implementing the LaunchDarkly SDKs

Init and Config

• SDK is initialized once as a singleton early in the application’s lifecycle
• Application does not block indefinitely for initialization
• SDK configuration integrated with existing configuration/secrets management
• Bootstrapping strategy defined and implemented

Client-side SDKs

• Application does not block on identify
• Application does not rapidly call identify

Browser SDKs

• Send events only for variation
• Bootstrapping strategy defined and implemented

Mobile SDKs

• Configure application identifier

Serverless functions

• Initialize the SDK outside of the handler
• Leverage LD Relay to reduce initialization latency

Using Flags

• Define context kinds and attributes
• Define and document fallback strategy
• Use variation/variationDetail, not allFlags/allFlagsState for evaluation
• Flags are evaluated only where a change of behavior is exposed
• The behavior changes are encapsulated and well-scoped
• Subscribe to flag changes