Just like programming, testing has significant context required, and switching contexts takes time. For anything less trivial than FizzBuzz the person testing w

Just like programming, testing has significant context required, and switching contexts takes time. For anything less trivial than FizzBuzz the person testing will need more than 15 or 30 minutes just to switch contexts. I can't see how a professional tester could make money on 30 minute slices of their time when they will need 30 minutes just to understand the problem, get access to or download the code, get set up to run it, and figure out the test cases. If I offered on-demand testing I would want at least four hours minimum. Once I get set up I could go through multiple test cases. At some point the setup time and context switch become a small part of the overall time. You can't expect someone standing by 24/7 ready to run your specific tests when you need them to, unless you pay them for that time. So to answer your question, the service you wish for doesn't exist because no one competent could make money with 30 minute chunks of testing, and the incompetent who would take the gig won't add any value.