Flagging at the Edge: Combining LaunchDarkly with edge functions

Serverless computing has revolutionized application development by eliminating the need for maintaining server farms or scaling applications manually. However, serverless applications often rely on numerous API calls, leading to latency and performance bottlenecks due to geographical distances between clients and servers. Edge computing aims to solve these issues by deploying critical portions of application code onto servers across multiple regions globally, reducing latency for many aspects of the application. This post explores popular edge function solutions like AWS Lambda@Edge and Cloudflare Workers, which are replicated across multiple regions globally. It also demonstrates how integrating these solutions with LaunchDarkly flags can enable powerful feature management and A/B testing capabilities without any client-side code. Lambda@Edge functions work similarly to regular Lambda functions but have some limitations on region, environment variables, and runtime. Users can integrate LaunchDarkly within a Lambda@Edge function using the server-side Node SDK. Cloudflare Workers are also serverless functions that work like AWS Lambda functions, with every Worker being an edge function deployed to Cloudflare's global network of CDNs. By integrating feature management and feature flags into edge functions, developers can quickly and transparently release features, change logic, adjust the HTML response, and more with just a switch in the LaunchDarkly dashboard. This enhances user experience by offering faster and better-performing applications while also enabling new possibilities for application functionality.