Rather than calling third-party APIs inline from core business logic, run integrations in dedicated adapter services with restricted network access and minimal permissions. The adapter processes the third-party response, validates and normalizes it, and passes only the safe, expected output to the core API. A compromise of the third-party or the adapter cannot directly affect the core API or database.
In a microservice architecture, the isolating pattern is natural: each integration gets its own service with its own deployment, network policy, and permissions. In a monolith, isolation can be achieved with module boundaries and strict validation at the module interface. Even simple isolation — a dedicated class or function that handles all third-party API calls and returns typed, validated output — reduces the blast radius compared to inline processing of raw API responses throughout the codebase.
Ask your architecture team whether a compromised response from any third-party API could directly affect your core database or business logic. Good isolation means the answer is no — a compromised vendor reaches an adapter, not your core system.