Self-Hosted Billing Anomaly Detection with FastAPI and Stripe Webhooks

Introduction Billing systems are the backbone of any subscription-based business. However, they can be vulnerable to anomalies, such as unexpected usage spikes or incorrect charge calculations. In this article, we'll explore building a self-hosted billing anomaly detection system using FastAPI and Stripe webhooks. Why Self-Hosting? While SaaS solutions like Stripe Billing offer ease of integration, they also come with limitations on customization, control, and cost. By hosting the solution ourselves, we can ensure: Data Privacy : Protecting sensitive customer data from unauthorized access. Cost Control : Avoiding unnecessary subscription fees or charges for usage beyond our needs. Customization : Tailoring the system to meet our specific billing requirements. Architecture Our system will be built around the BillingWatch architecture: Stripe Webhook Processing : Receiving and processing webhooks from Stripe for events like charge creations, updates, or deletions. Anomaly Detection Logic