We know events are one of the most effective ways to gather highly engaged leads — but even interested participants often forget to attend due to busy schedules or lack of calendar integration.

As event organizers, we already had access to a valuable database of potential attendees, some of whom were high-quality leads. However, we noticed a recurring issue: most people didn’t add the event to their calendar, resulting in low attendance rates.

To address this, I proposed and implemented a reminder system via WhatsApp, the most widely used communication platform in LATAM. The solution allows organizers to:

• Create multiple reminder variations per event
• Send automated WhatsApp messages to participants
• Use A/B testing logic during the invitation phase — the system tracks performance of each message and automatically selects the best one
• Embed UTM parameters in messages to enable conversion tracking and detailed analytics

From idea to launch, the full solution — backend and frontend — was designed and implemented in just two weeks, using QStash for scheduled message delivery and 2Chat as the WhatsApp API provider.