I don’t hire engineers because they already know the answers to problems. I hire engineers who know how to approach a problem and solve it. Sometimes that means a quick search on StackOverflow. Sometimes that means they dig into unfamiliar documentation to learn a new technology or API. If you only hire people who already know X, you’ll never find “the right” person, ever. Sure, hire people who have experience with Java, or PHP, or whatever your tech stack is, but often we’ve hired people who didn’t have deep experience in X but they were intuitive, smart people, eager to learn and apply those intuitive skills to the problem. The point is not to get hung-up on the “syntax” or even the mapping out of a problem. If all you’re hiring are code robots, you’re not building a team who work well with each other. That should be the goal. The knowledge will come quickly throughout the team if they don’t already know it.