After coding for almost 20 years now, full time, I have never regretted not using a dependency. But I have regretted using one multiple times.
(the regret is like a walk of shame during the "separation and cleanup" phase at the end, which makes me question the "got work done faster" phase at the beginning....)
If you've ever switched out dependency X for dependency Y I suppose you regretted not using Y to begin with.
If you've ever stopped working on your own solution to a problem and instead used a solution provided in a library didn't you regret not just using the library from the beginning?
nope, I am just saying what I said, I never regretted not using one, and have regretted investing in a few that later caused more headaches than they were worth.
When we switched from inhouse code to a dependency, we never regretted doing it on our own to start with because there was so much insight gained from this and many other side benefits (like direct control, intuitive understanding of how our code worked, etc...).
But when you have a dependency you add that you later have to work around, you simply can't fix in the same way can your own code, and you just hate the mess in a totally different way.
When it's your own code, you can fix anything. And replace it a piece at a time if need be. With a dependency, there's usually catches, hacks or work arounds, or conflicts built up over years that finally have come to a head. And it sucks to fix and in many cases if I had waited even a little while, or did more research at the time, I would have picked a different dependency or none at all.
There are a lot of dependencies we use, I don't think you can run a business properly these days without them. They just are not a part of our core systems anymore. We use them for tertiary systems and addons, things that a replaceable. Then our core systems can't be hijacked by stuff like the latest NPM debacle.
There are three reasons for this:
1) Those packages implement an ever-growing pile of tricks/heuristics to convincingly solve problems from the domain. They include: physics engines, SMT solvers, compilers/jitters/optimizers, computational geometry packages, video encoders ...
2) Those packages implement an unification layer over an ever-growing/evolving set of underlying APIs/protocols/formats. They include: SDL, ncurses, curl, ImageMagick ...
(these are not to be confused with "bug-factories" packages, which might not solve a complex problem, but still require constant updating to fix the current bugs, and benefit from the new ones).
> 1) [...]
> 2) [...]
Where is the third reason?
I can't speak for him and I don't know about you, but while deciding whether I would start to work on something, I'm actually deciding if I'm capable of doing it and looking at all the pieces needed to do it. I'm not starting work until I know I have all the pieces in place. Sometimes I may doubt that some piece is missing or might be hard to do, so I make a very small prototype of that system only (this usually takes a couple of hours tops). Once I make a decision and start working, I never go back.
Just like him, I have never regretted doing it myself, but have regretted using another developer's library many times.
Personally, I would rather see this than a bug fix being committed every week. That makes me question how many more bugs there are and how much I'm going to have to babysit updating the dependency.
That is a similar tactic I use now for anything core. I know I commented that we don't have any dependencies in our core systems, but as an afterthought, this isn't entirely accurate. We do, but as you said they are "legendary", and don't change a whole lot anymore.
I think you are on the right track. :)
Edit: Keep business practicality in mind, if using a 3rd party library means you feed your family or are productive for the business, you need to weigh these considerations carefully.
It's likely you need to use a dependency to get your work done, and then later when you are more profitable, you can clean it out if need be. Maybe that is how I should have worded my first comment in retrospect.
Many of these dependancies are open source. Nothing prevents you from copy/pasting the code and then maintaining it yourself. Then you alleviate the "hard to change" problem and you can vet it thoroughly inside your own team.
Then consider ditching this dependency (either by switching to a different one or with your own code) if the maintainers are not active enough.