Mallory Mooney and Christina Berardi discuss the importance of APIs in modular application development, highlighting their role in both internal services and public-facing datasets. They emphasize that APIs are a top target for threat actors due to their dual nature. The authors outline three types of threat actors: opportunistic, sophisticated, and internal, each with distinct motives and vulnerabilities. Opportunistic attackers exploit security gaps in publicly accessible APIs, while sophisticated actors use advanced social engineering techniques to gain access to intellectual property and data. Internal threat actors, often disgruntled employees or contractors, target misconfigured internal APIs. The authors identify API inventory management, authentication and authorization controls, and resource management as primary security threats, including poor inventory management, inefficient authentication and authorization controls, and unrestricted access to resources. To address these risks, teams should document and categorize their APIs using standards like OpenAPI, implement strong authentication mechanisms, and enforce the principle of least privilege. By understanding these vulnerabilities and taking proactive measures, organizations can enhance their API security strategy and protect against various types of attacks.