Separating Public APIs from Your Main Application: Best Practices for SaaS Platforms

In the world of SaaS development, scalability and security are paramount. Many companies prefer to compartmentalize their services to streamline maintenance and protect sensitive data. One common scenario involves exposing a public API for third-party developers—so they can build integrations, extensions, or new applications—while keeping the core application and its internal APIs protected.

The Core Question: Should You Host Public APIs on a Distinct Instance?

Imagine you operate a SaaS platform where the front-end and internal APIs are tightly integrated. Now, you’re considering opening up a public API endpoint to facilitate third-party development. Should this API be served from the same server as your internal services, or would it be better to deploy it on a dedicated server or subdomain, such as api.example.com?

Advantages of Isolating Public APIs

• Security: Separating public APIs reduces exposure of sensitive internal data and services, minimizing potential attack vectors.
• Scalability: A dedicated API endpoint can be scaled independently based on the demand from external developers, ensuring optimal performance.
• Maintenance & Deployment: Changes to internal APIs or core systems can be managed without directly impacting external-facing services, leading to a more organized development process.
• Rate Limiting & Monitoring: Isolated APIs facilitate better traffic management, analytics, and enforcement of usage policies specifically for third-party consumers.

Implementation Strategies

Many SaaS providers opt for deploying public APIs on separate instances or subdomains. For instance, setting up api.example.com as a standalone host allows you to:

• Manage authentication, authorization, and rate limiting separately from your main application.
• Implement targeted security measures tailored for external access.
• Streamline updates and maintenance without risking disruptions to your primary services.

Final Thoughts

While hosting your public API on the same infrastructure as your core application might seem convenient initially, adopting a separate hosting environment offers numerous benefits. It enhances security, encourages scalability, and provides a clearer boundary between internal and external services.

Ultimately, the decision depends on your specific needs and infrastructure architecture. However, for most SaaS platforms aiming to foster a healthy developer ecosystem, isolating public APIs on dedicated endpoints or instances is considered a best practice.