What is the best way to assess API performance in a single-page application?

Here are some best practices and tools you can use to assess API performance -Network Monitoring Tools -API Response Time Measurement -Load Testing -Error Handling and Monitoring -Caching Strategies -Endpoint Optimization -Content Delivery Networks (CDNs) -Performance Budgets -Real User Monitoring

For better performance of SPA, the API roll is very crucial. To have a better performance make sure the data while transferring the to be minimal and split the API’s as much as possible. Also, manage the calls to be redundant.

API performance shouldn't be negated. While concurrent users are widely used matrices for judging performance, RPS(Request per second) should also be right up there. Think about factors such as your infra location, from where you app is most being used, what's the latency difference when you serve requests to different locations. Try to adhere to the industry standard for the response time SLA, which is 500 milliseconds.

It's hard to understate the importance of API performance. Poor performance can lead to unexpected errors in your application, but more importantly, it creates a poor user experience. When an operation takes over half a second, users will become frustrated and may be less likely to use your application. If the operation takes longer than 2 to 3 seconds, users will give up or start refreshing the page, potentially leading to errors or duplicated operations. Minimizing the response times from your API can have wide-ranging benefits for your application and users.

For better performance of SPA, the API roll is very crucial. To have a better performance make sure the data while transferring the to be minimal and split the API’s as much as possible. Also, manage the calls to be redundant.

Here are some commonly used metrics for API performance, - Response times SLA(Industry standard is from 0.1 to 1 seconds max and 0.5 seconds average) - Request Latency, Server Latency - End to End Response Time, - Error rate - Error Types, - Throughput (RPS/Request Per seconds)

There any many kind of performance tests can be performance for API such as Load, Fail-over, Scalability, Endurance etc. But here are few things to keep in mind when designing a load scenario for APIs, 1. Concurrent users V/S Concurrent requests 2. API Throughput over time.(say, 100 RPS for 1 hour) 3. API Caching mechanism. 4. API authentication and authorization 5. Load Balancer 6. Sufficient Infrastructure provisions.

Load Testing: Beyond scalability, regularly conduct load testing to simulate various usage scenarios. This allows you to identify potential bottlenecks and areas for improvement. Fine-tune your API based on these findings to ensure optimal performance under different conditions. Simulate Network Throttling: Implement network throttling at the client or network layer to guarantee that your APIs and applications remain responsive even in low-speed networks.

1. To improve api performance make sure to use http2 as it provides faster connection and security as well. 2. Use a in memory cache like redis. 3. Use optimized database query. 4. Always normalize database table. 5. Last but not the least use nearest server. Like if you are from USA, you are not gonna use Singapore server. You will use nearby server as possible.

Caching Strategies: Employing effective caching strategies can significantly enhance API response times. Utilizing caching mechanisms for frequently requested data helps reduce server load and minimizes the need for redundant processing, leading to improved overall throughput.

Calling one REST API instead of multiple REST APIs can improve the performance of your application by reducing the network traffic, the server load, and the resource consumption. When you call multiple APIs, you have to send more requests and receive more responses, which increases the the load time. You also have to handle more errors and exceptions, which adds complexity and overhead. On the other hand, when you call one API, you can get all the necessary data in one go, without any unused information. This results in less traffic, less requests, less RAM and CPU usage, and less concurrent database operations. Therefore, calling one REST API instead of multiple can make your application faster, more reliable, and more efficient.

1. Define a API Response Time, Its optimal to have API response time less than 300 milliseconds. The faster the better. If any API is not meeting this threshold, look to optimise. 2. There are many tools to monitor API response times proactively and reactively. 3. Always prefer to proactive monitoring. Have a dashboard for the API response times and also for services that power the API. 4. Don't prefer composite API, Always prefer Single responsible API. SPA heavily rely on faster API's. So its critical for API response time should be less than 300 ms. So that users will get a intutive experience while interacting with SPA.