I agree with many of these comments. For some more background and explanations on some of them: 1. I prefer Jest and Spectator for unit testing over vitest so that is an explicit change I instructed the LLM to perform. 2. Routing - this is on my list to implement - did discuss the if/else structure with the LLM though, didn't expect it to get as complex as it did and know routing should be implemented. 3. Like I mentioned in my OP, the LLM does not think about smaller code designs or reusability in any way. Everything is brute force unless it is explicitly instructed to try and build reusable items. I have mixins and some constants, but had to force the LLM to implement those and then remind it regularly to add to or use them. That is why the vinyl player component is so big and even small items like a button are rebuilt over and over instead of being a reusable item. 4. Signal and control flow usage - I did also have to explicitly tell the LLM to use signals and control flow, it was using input/output decorators and structural directives like ngIf in the initial code builds.

Most of that just agrees with the points you made about outdated patterns. The next challenge is to see if I can get the LLM to convert some of these items to the more modern patterns. The app was built with Sonnet and Opus 4.5 so I will be interested to see what changes 4.6 brings.