API Facade

Problem

Applications often require diverse data from various APIs to function. These API calls can be cumbersome, particularly when each requires unique parameters and returns substantial data, most of which the application doesn't need. This unnecessary data not only slows down your application's performance but also increases the load on your network.

Moreover, individual API calls for different data sets increase the complexity of client-side code and elevate the risk of security breaches. Simplifying these API calls and optimizing the data received is critical for efficient application performance and security. This is where the Backend for Frontend (BFF) approach and the API Facade Pattern come into play.

Solution

The Backend for Frontend (BFF) design pattern allows developers to create client-specific APIs, which align with the specific needs and structures of different client types (mobile, web, etc.). The BFF serves as a middleware between clients and multiple backend services, simplifying the client-side code and optimizing the data served to each client.

Using BFF to create an API Facade involves creating "persisted operations" for clients. These operations are predefined GraphQL queries or mutations, REST Api Calls, or other upstream requests that reside on the server-side, requiring only a unique identifier to be executed. The identifier, often called an operation ID, is all that the client needs to send, minimizing network data transfer and boosting performance.

Furthermore, persisted operations enhance security. Since operation definitions are stored on the server, it drastically reduces the attack surface. An attacker can no longer send arbitrary operations; they can only execute the ones you've explicitly defined and exposed.

Implementing API Facade Pattern

Define the Persisted Operations: The first step involves defining the necessary operations (queries or mutations) that your clients are expected to perform. These operations are stored on the server.

Assign Unique Identifiers: Each persisted operation is assigned a unique identifier or operation ID. This ID is used by the client to trigger the operation.

Create BFF API Endpoints: Using the BFF pattern, create client-specific API endpoints. Each endpoint should be designed to cater to the unique needs and data requirements of each client.

Client Calls: Instead of making API calls with large request bodies, the client can now simply send the operation ID, drastically reducing network data transfer.

Benefits of API Facades

Optimized Performance: By reducing the size of requests and responses, you effectively reduce network load and latency, resulting in faster applications.

Improved Security: Since the operations are predefined and stored server-side, there's less opportunity for malicious attacks.

Simplified Client-Side Code: Clients need only send an operation ID, making the client-side code simpler and easier to maintain.

Leveraging the API Facade Pattern with persisted operations can significantly optimize network data transfer, enhance security, and improve overall application performance. By aligning API operations with specific client needs, you can build more efficient, secure, and high-performing applications.