SmsDispatcher

SmsDispatcher was a solution that allowed businesses to send automated SMS messages at dramatically lower costs by leveraging consumer mobile plans instead of expensive SMS gateway APIs.

The Problem

Traditional SMS APIs (Twilio, Vonage, etc.) charge per message — typically between 3 and 7 cents per SMS. For businesses sending thousands of messages monthly (appointment reminders, notifications, marketing), this adds up fast.

Meanwhile, consumer mobile plans in Belgium offer thousands of SMS for a flat monthly fee of a few euros. The gap between these two pricing models was the opportunity.

How It Worked

• Android relay devices — Consumer phones with cheap unlimited SMS plans, connected to a central server
• REST API — Businesses integrated with a simple API to queue messages
• Smart routing — Messages distributed across multiple devices to avoid rate limiting and carrier flags
• Delivery tracking — Confirmation callbacks when messages were sent and delivered

Lessons Learned

This was one of my first real projects — built during university, before I had any real sense of production engineering. It worked, it had real users, and it taught me more about API design, reliability, and the gap between “it works on my machine” and “it works at scale” than any course ever could.