I'm the solo developer behind Lynq. I originally wanted to offer a live demo that would provision a short-lived tiny app in real time so people could actually watch it boot and vanish. It was a fun idea, but running that safely on small homelab-style infrastructure didn’t feel solid enough for security or traffic spikes.
So I switched to providing the demo through KillerCoda instead. It gives a clean, isolated environment where you can try the workflow without setup. Just sharing in case it's useful.
It is not open source, but I am still proud of a message delivery system I designed and built alone two years ago. It consists of six independent components and guarantees at least one successful delivery as long as the database remains available. It supports AWS SES, Twilio SMS and MMS, Webhook, Discord messages, and can easily add new providers through an adapter pattern.
Messages are queued through an API, captured by Debezium, produced to Kafka, delivered by workers, logged, and updated through DSNs received via webhook. Failures go to a DLQ where they are retried until the limit is reached.
Each stage runs independently, so any failure only causes minor delay without risking unintended drops. With Prometheus metrics in place, this system has processed more than two hundred thousand messages per day in production for two years without a single reported loss.
So I switched to providing the demo through KillerCoda instead. It gives a clean, isolated environment where you can try the workflow without setup. Just sharing in case it's useful.