Another thing about seasoned professionals - they have top-down and bottom-up knowledge of how their product works. They can discard a lot of superfluous information out of hand, which allows them to narrow the scope very quickly.

So when a newb is parsing an error log, they look at any and all related errors. 90% of their mental capacity is being used to judge each entry, asking themselves “Is this thing relevant to the problem?” Chasing red herrings.

Meanwhile, the senior engineer can glance over and see the 100 lines of network errors are just an uncaught exception from a deprecated module because a line of code never got commented out. Or some such shit.