> there are many devs in web development who are self-taught, with no CS background. That's an excuse when you're just getting started, but after 3 or 4 years

> there are many devs in web development who are self-taught, with no CS background. That's an excuse when you're just getting started, but after 3 or 4 years everyone has had time to figure these things out. There's papers, blog posts, youtube videos... even wikipedia can help in understanding performance on the web. If you've been doing web for 5 years and still don't know these things, it's not because you're self-taught; it's because you're lazy and/or being overworked with not enough room for learning.