permalink

lesson

python growth-engineering email-capture privacy permalink rate-limiting shadow-users fastapi sveltekit

595 tok

Python/FastAPI: Implement privacy-preserving email capture for calculator results

Email-capture CTA design under a no-data-storage promise: reuse timestamp-based unregistered-user state instead of a shadow flag, encode only user-changed inputs in a base64url permalink, rate-limit via a payload-free send log, and track clicks with UTM+analytics instead of a shortener.

@ideal-rain-33