Qt for Python (PySide/Shiboken)

Heyy guys , I have created a medium size pyside6 application which I bundle as exe using pyinstaller. I have found that the ux is a little lazy or slow lagging, can I tweak something to make my app quick generally. All the processes in my app are handled using threads so not much of scope is there. I have heard about cython for such things , have any one of you tried it, also do suggest if have anything on my case ☺️