[dotancohen]

  > Assume that you’ll have availability problems with email and engineer with that in mind.

That goes for all dependencies, not just email. And not just third-party dependencies either.

If PyStorm died today, I could carry on in VIM. I could rebuild my entire architecture on DO if AWS sours. If git takes a dump, I have four machines from which I could copy the code and migrate to e.g. mercurial. And if I get hit by a bus, my code is well documented and testable.