What are the best practices for reviewing code that uses caching or performance optimization techniques?

1 Identify the goals and trade-offs

Before you dive into the code, you should understand the goals and trade-offs of the caching or performance optimization strategy. What problem is it trying to solve? What metrics are used to measure the improvement? What are the potential risks or drawbacks of the approach? How does it affect the readability, maintainability, and testability of the code? Asking these questions can help you evaluate the effectiveness and suitability of the solution.

2 Review the cache configuration and invalidation

Caching can reduce the load on the server and improve the response time of the web application, but it can also cause stale or inconsistent data if not configured or invalidated properly. You should review the cache configuration and invalidation logic to ensure that they match the requirements and expectations of the application. For example, you should check the cache expiration, size, location, and key generation policies, as well as the events or conditions that trigger cache updates or evictions.

3 Review the performance optimization techniques and tools

Performance optimization can involve various techniques and tools, such as minification, compression, bundling, lazy loading, prefetching, and parallelization. You should review the performance optimization techniques and tools to ensure that they are applied correctly and consistently throughout the code. For example, you should check the quality and compatibility of the minified, compressed, or bundled files, as well as the impact of lazy loading, prefetching, or parallelization on the user experience and resource consumption.

4 Review the code quality and style

Caching and performance optimization can sometimes compromise the code quality and style, making it harder to read, understand, and modify. You should review the code quality and style to ensure that they follow the best practices and standards of the web application. For example, you should check the naming, formatting, indentation, comments, documentation, and modularity of the code, as well as the use of constants, variables, functions, classes, and modules.

5 Review the tests and metrics

Caching and performance optimization can sometimes introduce bugs or side effects that are not detected by the regular tests. You should review the tests and metrics to ensure that they cover the caching and performance optimization aspects of the code. For example, you should check the unit, integration, and end-to-end tests, as well as the performance, load, and stress tests, to verify the functionality, reliability, and scalability of the code. You should also check the metrics and logs to monitor the performance and behavior of the code in different scenarios and environments.

6 Provide constructive feedback and suggestions

Caching and performance optimization are not one-size-fits-all solutions. They require careful analysis, experimentation, and evaluation to find the optimal balance between speed and quality. You should provide constructive feedback and suggestions to the code author to help them improve their caching and performance optimization skills and practices. For example, you should praise the good aspects of the code, point out the issues or risks of the code, and propose alternative or better solutions or resources.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?