The last time you chose a new framework or library, was it because your problem needed that tool, or because it sounded cool and few people around you were using it? That question is uncomfortable. Technology decisions are often made for reasons that never appear in any technical document.
Three scores, one division, and the average prints as 82. Both operands are int, so the fraction is cut off, and the obvious cast prints 82.0 without fixing anything.
You pull one function out into its own file, import it, and the whole report runs again and eats your input. A module is a file, import runs it top to bottom, and one line decides which of the two jobs it is doing.
Same model, same conversation, same token count, and a bill five times higher. The cause is a prefix that changes, a write premium nobody reads about, and a cost curve that grows faster than the loop.
Streaming moves the wait into a connection that outlives the request. Four layers sit between the model and the browser, their idle timeouts disagree, and the smallest one ends your stream.