[talkingtab]

My opinion: rolling your own does have a higher initial cost, but it can have a much lower long term cost. Consider the case where you need a very small modification to the dependency. In many cases that will require a much greater investment because you will now have to a) understand the dependency, b) make and test the change and c) support the change long term (unless it is folded into the mainline). Also consider the case where some dependency or specification changes (way too frequently) or there is a bug that you desperately need fixed. What do you do then? Technical debt. For me then, understanding the probability and consequences of events like that is important.

[jklm]

One thing I’ve gotten better at over the years is identifying the viability of off-the-shelf tools early on. If you minimize subpar tooling at the source, you can mitigate long-term frustration down the line.

[tomxor]

Yes this is my point, upfront cost for a dependency is obviously zero (well maybe not zero if you include the cost for learning someone elses interface and integrating it into your code), it's always later that you pay in unforeseen ways.