Email API showdown: testing Mailgun vs. Resend with LaunchDarkly feature flags

This tutorial demonstrates how to use LaunchDarkly feature flags to toggle between two different email providers (Resend and Mailgun) in an ExpressJS application. The process involves setting up a development environment with Node.js, git, and npm installed, creating accounts for Resend, Mailgun, and LaunchDarkly, and then building the example ExpressJS application. By using feature flags, developers can more safely migrate from one email provider to another or use multiple providers as primary and backup services.