Dear new developer,
Sometimes you want to play out things two and three steps deep. Kinda like chess players, who think about many moves ahead, if you can consider the ramifications of your decisions, you’ll be well served.
I remember talking to someone about a software position at his company and he referred to the “original sin” of choosing a particular NoSQL database. This had ripple effects throughout the life of the company. Some were good, some were bad.
These kind of downstream effects are worth thinking about. The biggest ones are things like fundamental platform choices (Rails or Django, Java or golang, mysql or postgresql). But even smaller things can have ripple effects. I can’t count the times when I’ve said “I’ll just upgrade this one thing” and then the change just keeps cascading out.
Or if you are working on a feature definition, think through the ramifications. “We want to allow people to change their email address.” But if email address is the primary key of a table, or a primary means of connecting data across accounts, or some other invariant, what will the ripples in your system be.
And these are just the functional repercussions. There are also performance repercussions to changes, some of which are hard to test unless you are in production.
I’m not saying don’t accept changes. That way lies madness (and Fortran). Just be aware of how changes in complicated systems like web applications have a way of rippling out beyond their intended scope, and consider how to test, mitigate or handle such ripples.