Best state management library in Javascript

Scheduler Design Help Needed

Basically I am designing a system, which can have thousand of cron jobs. I am creating a UI where one can create cron job, and specify the interval in it. What system design you will suggest making it scalable?

Which e2e testing framework you are using?

Which e2e testing frameworks you are using. I got some idea from article https://dev.to/dennismphil/automated-end-to-end-tests-made-easy-180m but still, I am curious to know.