Apache Flink is the foundation for Decodable's real-time SaaS data platform. Flink runs critical data processing jobs with strong security requirements. In addition, Decodable has to scale to thousands of tenants, power various use cases, provide an intuitive user experience and maintain cost-efficiency. We've learned a lot of lessons while building and maintaining the platform. In this talk, I'll share the top 3 toughest challenges building and operating this platform with Flink, and how we solved them.