programming, when stripped of all its circumstantial irrelevancies,
boils down to no more and no less than very effective thinking so as to avoid unmastered complexity,
to very vigorous separation of your many different concerns.
-- Dijkstra EDW512
https://www.cs.utexas.edu/users/EWD/transcriptions/EWD05xx/EWD512.html
"Boundaries" - Gary Bernhardt
https://www.youtube.com/watch?v=yTkzNHF6rMs
https://www.destroyallsoftware.com/talks/boundaries
https://www.destroyallsoftware.com/screencasts/catalog/functional-core-imperative-shell
there are only two roles of code - John Sonmez
https://simpleprogrammer.com/2012/10/21/there-are-only-two-roles-of-code/
Object layer, valuelayer (starting at 27 minutes 53 seconds) - Andy Matuschak
https://realm.io/news/andy-matuschak-controlling-complexity/
"Functional core & Imperative shell" : OO design, and isolated tests without mocks
http://blogs.perl.org/users/mascip/2014/06/functional-core-imperative-shell-oo-design-and-isolated-tests-without-mocks.html
http://blogs.perl.org/users/mascip/2014/06/functional-core-imperative-shell-explanation-with-code.html
A Modern Architecture for FP - John A De Goes
http://degoes.net/articles/modern-fp
http://degoes.net/articles/modern-fp-part-2
Business-Friendly Functional Programming, Part 2: Testability - Yang Bo
http://rea.tech/business-friendly-functional-programming-part-2-testability/
mokacoding - unit and acceptance testing, automation, productivity
http://www.mokacoding.com/blog/functional-core-reactive-shell/
Functional Core, Imperative Shell - Sean Hammond
http://www.seanh.cc/posts/functional-core-imperative-shell
BoochTek, LLC
http://blog.boochtek.com/category/programming/architecture
Functional Programming in Ruby - Vitor Capela
https://speakerdeck.com/dodecaphonic/functional-programming-in-ruby
Enemy of the State by Justin Spahr-Summers
https://speakerdeck.com/jspahrsummers/enemy-of-the-state
Functional Programming in Swift - slide 55+
http://www.slideshare.net/SaugatGautam2/functional-programming-in-swift
Test-Driven Development with Python - Harry Percival
https://books.google.dk/books?id=fTLJAwAAQBAJ&pg=PA403&lpg=PA403&dq=%22functional+core%22+%22imperative+shell%22&source=bl&ots=A4g25w7wWY&sig=x0bu4NZWiXrpzWPziAH7Y78AKgM&hl=en&sa=X&ved=0ahUKEwi0jq3em-zPAhUqG5oKHYNJBIE4ChDoAQhRMAk#v=onepage&q=%22functional%20core%22%20%22imperative%20shell%22&f=false
Growing Object-Oriented Software, Guided by Tests Without Mocks - Vladimir Khorikov
http://enterprisecraftsmanship.com/2016/07/05/growing-object-oriented-software-guided-by-tests-without-mocks/
Test Isolation Is About Avoiding Mocks - Gary Bernhardt
https://www.destroyallsoftware.com/blog/2014/test-isolation-is-about-avoiding-mocks
To Kill a Mockingtest - Ken Scambler
http://rea.tech/to-kill-a-mockingtest/
Mocking is Tautological - Mark Sands
http://marksands.github.io/2014/05/14/mocking-is-tautological.html