"Don’t underestimate the value of digging into history to investigate some bugs." Valuable advice, and it particularly highlights the risk of global state and the benefit of understanding your runtime. Browsers have popularized flamegraphs, stack traces show you the frames down to the moment of error, but global state survives multiple stack traces and the one you're looking at may not be (probably isn't) the cause of the problem. There is global state, the heap, external systems, etc that change over time and with successive calls. This is true even in single-threaded environments, and is far more complex in general multi-threaded environments. I often feel this isn't clear to beginners nor is it clear to them how you go about investigating bugs within this context.
