A declarative approach using GraphQL directives can be used to secure APIs in the financial services industry by enforcing authentication and authorization for specific fields or types in the schema. This approach allows developers to centralize security logic, making it easier to manage and maintain across the entire API surface area. With a directive-based authN/Z solution, teams can implement standard policies, share metadata with other teams, and empower client developers to understand API access requirements. By using Apollo GraphOS, developers can power essential features of modern financial applications while ensuring compliance with regulatory standards.