This can truly cut in either direction, and one of the benefits of long experience is learning to judge the over and unders on what is often a crucial educated

This can truly cut in either direction, and one of the benefits of long experience is learning to judge the over and unders on what is often a crucial educated guess. Certainly, though, it's disastrous to assume that some existing library/product/whatever is going to be superior to home-grown, just because a lot of people use it, there's a big company behind it, or etc. That piece of software was written to cover a certain area of design and business space, and that may not intersect very well with the design and business space you need covered. For myself, I do start with the hope that I'll be able to avoid writing some big chunk of code (by using some existing piece of software). But I'm very wary, as external software comes with costs, even if it's "free".