False sense of security sold by conference indsutrial complex is my biggest issues with unit testing. One time I've seen a junior dev wrote copious amount of un

False sense of security sold by conference indsutrial complex is my biggest issues with unit testing. One time I've seen a junior dev wrote copious amount of unit tests to achieve near 100% code coverage. When this "perfect" code went into prod it almost took the whole system down. Because the junior dev was joining close to a dozen tables and each one of the tables has at least a million rows. If the junior dev took the time to understand basic DB performance instead of writing dozens of unit tests, then it wouldn't have happened. I blame the gurus who don't write code for living, but peddle magic solutions like "clean code", unit testing etc. to sell more books and seminars.