Optimizing API Gateway Strategies: Balancing Endpoint Granularity and Cost Considerations

In the evolving landscape of API architecture, selecting the right gateway approach can significantly impact both system design and operational costs. Recently, I encountered a scenario that prompted me to reflect on best practices for managing multiple endpoints, particularly when vendor pricing models favor fewer, consolidated actions.

Understanding the Context

Imagine a system with a set of controllers that handle various operations on resources — for example, a WidgetsController with actions like CreateWidget, GetWidgets, UpdateWidget, and DeleteWidget. Additionally, there are specialized actions tailored for specific use cases, such as GetWidgetsForUseCase1 and GetWidgetsForUseCase2. These are designed to encapsulate distinct business logic tied to particular workflows, maintaining clarity and separation of concerns.

Our backend maintains a DRY (Don’t Repeat Yourself) approach, centralizing shared logic within service layers. The use-case-specific endpoints primarily exist at the controller level for clarity rather than duplication.

Vendor Recommendations and Concerns

During evaluation, a vendor raised a noteworthy point: their pricing model charges based on the number of actions or endpoints. This suggestion leads us to consider reducing the total number of endpoints by combining similar actions into a more versatile, parameter-driven endpoint. They also recommend leveraging their gateway tooling to handle internal logic based on flags or request parameters.

While this approach might seem advantageous from a cost perspective—reducing the number of billed actions—it raises questions about architectural integrity and maintainability. Is such consolidation beneficial beyond monetary savings, or does it risk obfuscating the API’s intent and making future modifications more complex?

Key Considerations

1. Architectural Clarity vs. Cost Efficiency
   Maintaining narrowly scoped, purpose-specific endpoints promotes readability and easier troubleshooting. Combining multiple behaviors into a single endpoint necessitates intricate internal logic, which could obscure the API’s intent.

2. Performance Implications
   In many cases, consolidating endpoints requires additional conditional checks and processing, which might marginally impact performance. However, modern infrastructure often mitigates this concern, making architectural clarity more critical.

3. Scalability and Future Growth
   As we anticipate introducing more endpoints with varying responses, a single, complex endpoint could become unwieldy, complicating testing and documentation efforts.

4. Vendor Lock-in and Pricing Models
   Relying heavily on vendor-specific features or pricing schemes