My current programming project, my goal has been to do as much in-app as possible. Does that mean I'm more likely to have bugs in my own code? Yes. But I've learned a ton doing it, and I know that my code doesn't have a giant monster of bloat hidden behind some random dependency somewhere. And yeah, that means when I wanted to handle email, I learned a heck of a lot about how programs handle email. Did it take more time? Yup. Education is time well spent.
I've got two dependencies besides the basic framework my project is built on: A scheduling engine, and a database interface. I eventually hope to factor out both.
That's true, I don't. But if your deadline is too tight to do it right, maybe you need to reevaluate your project plan.
I mean, I can certainly see using more dependencies than I'm using. Mail is a great example of something that probably should be handled by dedicated, well-tested code. But to carelessly dump piles of third-party dependencies in your project to save a few minutes, as talked about in this article... just crazy.
I've got two dependencies besides the basic framework my project is built on: A scheduling engine, and a database interface. I eventually hope to factor out both.