[pentaphobe]

The most consistent non-durability I see these days is business logic intertwined with external (API / file system / env vars) resource access - all scattered throughout layers of a codebase.

(Basically a violation of Factor IV in "Twelve Factor App" [^1])

Certainly not the _only_ durability concern present, but it seems to crop up more extremely and in more places.

Dependency Injection can help mitigate this a little but seems to often be a crutch which covers for poor architecture and enables eventually atrocious readability (a sad admission as I'm fundamentally a fan)

TLDR I find a good question to ask is whether the core logic and journeys can be executed in total isolation from any real resources. If it can't, you'll likely have a rough time testing, maintaining, or scaling - or at least changes will be more troublesome than they could be

(NB: bunch of sibling comments saying similar - but felt worth highlighting the local-first / isolated / separable aspect)

[1^]: https://12factor.net/backing-services