What’s more challenging? Coding bootcamp or a software engineer job

This is really hard question to answer. The majority of engineers I've seen grow form zero to N over their careers haven't grown linearly... they grow exponentially. So what you perceive as mind bogglingly hard during a bootcamp, will come across as trivial later on. But what you perceive as mind bogglingly hard as a junior engineer, will come across as trivial when you are senior. Now how you "feel" is a lot about you. The work ethic to succeed in a top bootcamp like Codesmith, HackReactor, Rithm, etc... is higher than most jobs, and even FAANG jobs would need to meet expectations. If you want to coast as a junior engineer for a long time then you might even find the work "intellectually" easier. If you want to always grow, learn, and improve, then you will always feel like everything is hard. Over time those things might shift to "people skills" rather than just raw coding skills. The main difference is confidence. You might feel challenged later on in your career, but you'll have some savings in the bank, and a lot of pats on the back behind you. When you start out in a bootcamp it's a tough emotional spot to be in, bottom of the totem pole and no clear path to start climbing.