DesignPremium EpisodesS9 Premium Episode #615 Mistake-Proof API Avdi Grimm February 28, 2020 2 Comments Members only Log in below or get 48-hour access for $5. Need more time? See all available plans. Username or Email Address Password Remember Me Related CategoriesDesign, Premium Episodes, S9 PremiumTagsapi design, errors, input data validation, oop, user input, verification and validation