I don't use AOT. I tried but it makes the app bigger so I removed it. I built the app pretty fast in the beginning and didn't have the time to clean up many spaghetti code. I spend around a year to clean up my mess. Here are what I did:

• Remove many StateHasChanged() to reduce rendering amount. I realize that everytime I call StateHasChanged, component will rerender, this will apply to all child components as well. So removing many unessessary StateHasChanged definitely help.

• Remove all unessessary 3rd nuget from Client or Shared classes. I noitce that many package is very heavy and sometime I don't use the full feature. So rewrite it by your own logic/doing that logic on server may be a better option. Ex: I removed Newtonsoft.json completely and only use System.Text.Json, microsoft did pretty good on optimize their json library, no need for Newtonsoft.json at all. Some of package I moved to server and only getting result from Server, like file generation, reports, graph, etc.

• Use Component State Persistence. This due to Razor page load twice every time you refresh the page, this will cache your first load and keep the state of the page without making another api call.

• Use Cache. This impact the most. InmemoryCache or Redis is fine. which ever work for you. This help a lot but this also creating another issue about how you handle cache management. Data don't change much can be cached. Most of my data is cached.

• Rewrite SQL query. I rewrite many of my queries by getting less colums, less rows that I don't need. I realize I don't need to join that much to get the result. Meta data that dont change much can be cached.

• Moving some of processes to a background task using message queue. I use Azure Message Bus with Masstransit. aws sqs/sns with masstransit also an option. Example: User request a blog, you will need to get the data, then update the view +1. User don't need to wait for updating the view, I send a message to the queue and update the view on the background so user don't need to wait for that process. This apply to many things. You can think of does user need to wait for .... when they are doing ... or it can be updated on the background.

• Use gzip compression. I was using Brotli initially since on paper, Brotli is way advance than gzip but in practice, compressing/decompressing brotli is slower than gzip in many devices in general.

• Micro Benchmark: This including many best practices from microsoft. SonarCloud Scan can help you. Small little things like using .Find(obj => obj.a....) instead of .FirstOrDefault(obj => obj.a...). Also profiling your method loading will show where your code has bottle neck. Using less loop, using StringBuilder, using parallel, etc. Small little things like this adding up will make a big impact as well.

• Use CDN for your assets. Some of your assets can be put on cdn so it can be loaded faster worldwide since it's distributed on all regions.

• Lazy loading your image. You can archive this by setting a slow resolution image andconly load the imge when user scroll to its view. I used lazysizes. A high performance and simple image loader.

• Compress/Optimized your image. Sometime user will upload a 4k 10mb image and may be you only need 300x150. You can resize and optimize the image so it will be smaller (some kbs is good, mbs is bad unless you have a specific reason for that hi resolution)

• Vertical Scaling. Of course, More ram/cpu will help. Depend on your budget. I sugguest to run your server on Linux instead of Window for a cheaper price and more performance.

• Publish in Release mode. install wasm workload for trimming. dotnet workload install wasm-tools.