Performance Optimization for Followers/Following Page Load Times

[petecheslock]

Context

The followers page has been experiencing significant slowdowns in production, leading to a poor user experience. Initial analysis pointed to multiple potential issues, including inefficient database queries, the N+1 query problem, and suboptimal data handling during rendering.

Improvements Made

Database Queries Optimization: Implemented indexing on the users and relationships tables to speed up query execution. This change was guided by the observation of slow database access patterns for follower data retrieval.

Eager Loading to Combat N+1 Queries: Modified the data-fetching logic to use .includes for eager loading associations. This change directly addresses the N+1 query problem observed in our AppMaps, where each follower's details were fetched in separate queries.

Rendering Efficiency: Improved the rendering process by introducing partials and collection rendering for followers. Additionally, implemented caching strategies for parts of the page that are less dynamic, significantly reducing the server's work during page rendering.

Pagination Implementation: Implemented pagination for the followers list to limit the number of records fetched and rendered on each page request. This approach not only speeds up the page load but also improves the user experience by not overwhelming them with too much data at once.

Benchmarking and Monitoring

Utilized Rails' built-in benchmarking tools to measure the performance improvements, with a noticeable decrease in page load times and query execution times. Monitoring will continue to ensure that the changes remain effective under varying loads.

Next Steps

Future considerations include further optimizing the cache strategy and exploring additional areas in the app where similar performance improvement techniques can be applied.

[github-actions]

AppMap runtime code review

Summary	Status
Failed tests	✅ All tests passed
API changes	0️⃣ No API changes
Security flaws	✅ None detected
Performance problems	✅ None detected
Code anti-patterns	✅ None detected
New AppMaps	0️⃣ No new AppMaps