What is important when roasting
Coffee roasting is presented to the outside world as a very complicated process, and anyone looking for information on the internet will be overwhelmed at best.
The fact is, however, that there are some (obvious and unspectacular) factors in coffee roasting that have such a clear effect on the flavour that everyone can taste it. And there are many factors that even very experienced roasters can barely taste in blind tastings - and yet it is precisely these barely relevant factors that are often emphasised. You shouldn't let this confuse you, because the only thing that matters is that the coffee tastes good.
And here we come to one last important preliminary remark - flavour preferences are extremely different from person to person, so you should really pay attention to your personal sensory perception and concentrate on what YOU like.
Work your way step by step through the factors that have a relevant influence on flavour - from big to small: