For a while, I offered to analyze the performance of any production web service people sent me. This series records the analysis of four of those services. Because they are real sites running in production rather than made-up examples, they include the problems you actually run into in real codebases, such as bundle composition, rendering strategy, and library choices.
Each part includes the analysis along with the feedback the developers sent and answers to their follow-up questions. Some questions went beyond the analyzed service, such as optimization strategy for admin services, so I hope these are useful for other services in similar situations.
Thank you again to the developers who requested the analysis and gave permission to publish their feedback.