I consider myself aware of the concepts of threading and why certain code is or isn’t “thread-safe,” but as someone who primarily works with ASP.NET, threading and thread safety
Only if you create, within the processing stream for a single HTTPRequest, multiple threads of your own... For e.g., if the web page will display stock quotes for a set of stocks, and you make separate calls to a stock quote service, on independant threads, to retrive the quotes, before generating the page to send back to the client... Then you would have to make sure that the code you are running in your threads is thread-safe.