Are you slowed down by rerunning tests failing randomly at CI? Or maybe you see a green test on your machine and your teammate claims it's red on their computer? I have bad news: you may have caught the Flaky Test Syndrome!

Treat this talk as a way to boost your developer immune system against the illness of unpredictable tests. We'll write and analyse seemingly innocent tests that hide the ugly germ of flakiness. From global state through date and time issues to OS-specific differences, we'll cover various cases that make a test non-deterministic.

After this talk you'll be able to write a flaky test (yay!), but more than that. You'll understand what makes a test non-deterministic, how to detect them and what to do to avoid creating them.