Build a self-hosted deep linking and referral system for React Native without a third-party SDK. This guide covers Android App Links, iOS Universal Links, an S3 and CloudFront setup, and a NestJS backend that routes users to the right app store.

Third-party attribution services like Branch, AppsFlyer, and Firebase Dynamic Links offer turn-key deep linking out of the box. However, they frequently bring vendor lock-in, recurring SaaS subscription overhead, privacy and data residency compliance challenges, and sudden deprecations (such as the sunsetting of Firebase Dynamic Links).

Firebase Dynamic Links is the clearest example: Google shut the service down on August 25, 2025 , and every page.link URL stopped working on that date.

This guide walks through building a fully self-hosted, vendor-agnostic deep linking and referral system using native OS domain verification, AWS infrastructure (S3, CloudFront, Application Load Balancer), a NestJS backend , and a React Native mobile client.

What Is Deep…