How have side-effects complicated your code base?

Question

I recently read "Out of the Tarpit", where the claim was that state management and side-effects was a big cause of complexity in our code bases. Wanted to hear concrete stories of whether that was true.A friend was telling me that he had to write a user onboarding flow involving external APIs like Stripe and Mailchimp. Writing it and testing it involved setup on staging accounts and mocking the objects that got returned from the service.I was wondering if HN had any war stories about how side-effects really made your code base more complicated and made your job harder. Or maybe it wasn't, and you were able to find easy ways to mitigate state management/side effect complications?

PaulHoule · Accepted Answer

Not as much as the lack of side effects complicates your code when you're struggling with concepts like "A Monad is Like A Burrito".The whole point of a lot of code is to have side effects.