Amazon Web Services (AWS) Customers use the Virtual Private Cloud service to virtually provision networks to connect their cloud-based applications. As customer’s scale their networks in order to meet their business goals it becomes more and more challenging to determine if their applications continue to meet their security and compliance mandates. Late last year AWS launched Network Access Analyzer, an automated reasoning-based service to help customers better understand if their networks satisfy such mandates. In this talk, we will discuss how customers are using Network Access Analyzer to formally prove that their networks meet their network compliance requirements.