Building an Instagram AutoDM System at Scale: Webhooks, Event Driven Architecture, and Lessons Learned

Instagram creators love engagement. Every comment is an opportunity to start a conversation, share a product, deliver a resource, or convert a viewer into a customer. The problem is that manually replying to hundreds or thousands of comments doesn't scale. At Vyral , we set out to build an Instagram AutoDM platform capable of serving thousands of creators while handling bursts of traffic generated by viral Reels. Instead of building a traditional chatbot, we designed an event driven system powered by Instagram webhooks, AWS services, and asynchronous processing. This article walks through the architecture, the engineering challenges we encountered, and the lessons we learned while designing a system that can process large spikes of comment events reliably. The Problem Imagine a creator with 2 million followers. A Reel starts trending. Within minutes: 10,000+ comments arrive Thousands of users comment the same keyword Instagram sends webhook events continuously Every eligible comment should trigger a personalized DM From an engineering perspective, this isn't a chatbot problem. It's an event processing problem. The system needs to answer questions like: Which comments qualify? Has this comment already been processed? What happens if Instagram sends the same webhook twice? What if the user deletes the comment? What if our service is temporarily unavailable? How do we avoid overwhelming downstream APIs? Those questions shaped the architecture far more than the messaging logic itself. Why We Chose Webhooks Instead of Polling Polling Instagram every few seconds would have introduced unnecessary latency and API usage for Vyral AutoDM . Instead, Instagram pushes events whenever something happens. The flow looks like this: Instagram │ ▼ Webhook Endpoint │ ▼ Event Validation │ ▼ Event Queue │ ▼ Workers │ ▼ Business Rules │ ▼ Send DM This architecture offers several benefits: Low latency Lower infrastructure cost Better scalability Natural decoupling between components Most i