Yes, QA is important. My code will always "work" in that everything I tested is bug free. But having someone other test, especially someone who knows the service is gold.
But there is also bad QA: The most worthless QA I was forced to work with, was an external company, where I, as developer, had to write the test sheet and they just tested that. Obviously they could not find bugs as I tested everything on the sheet.
My most impressive QA experience where when I helped out a famous Japanese gaming company. They tested things like press multiple buttons in the same frame and see my code crash.
But there is also bad QA: The most worthless QA I was forced to work with, was an external company, where I, as developer, had to write the test sheet and they just tested that. Obviously they could not find bugs as I tested everything on the sheet.
My most impressive QA experience where when I helped out a famous Japanese gaming company. They tested things like press multiple buttons in the same frame and see my code crash.