For those building on the Assistants API: biggest speed improvement: setting up thread ahead of time.
Runs have messages on them and are within a thread. My biggest speed improvement came from splitting part one. Basically when the user opens my bot by clicking on the + symbol, it sends a message to the backend to initalise a thread and have it ready. Then when the user send the message, the run is added to the thread. Thread ends when the user closes the bot