One abosolutely should be prioritized over the other. There's never going to be a situation where you can address every potential source of slowdowns, and make

One abosolutely should be prioritized over the other. There's never going to be a situation where you can address every potential source of slowdowns, and make everything 100% efficient all of the time. Given that, in any somewhat realistic environment, you're going to need to prioritize where to spend your focus on making things more efficient. It's certainly possible that the answer is that the language you're using is fundamentally too slow - I personally have almost never experienced that - almost always I can get more out of a time investment by focusing on improving DB performance, or some problem with delivery, caching or optimizing bundles. You should look at your personal situation and use real data to decide where to focus, but you always have to focus. "Make everything 100% efficient at all times" is completely unrealistic.