Rails
Created a basic Ruby on Rails app. This app only exposes a REST API.
The learning curve for Rails is interesting.  I started building a model before
I found out about Request Specs.  So, I shifted to an outside-in approach and
wrote a request spec first.  Then, I found out about rails generate scaffold,
which generates a bunch of tests automatically.  Most of them already do useful
stuff straight out of the box.  I just needed to supply a tiny bit of code to
get them all to pass.  I’m not 100% sure how that jives with TDD, but is sure
feels rather efficient.
I used Ruby 2.4.3 and Rails 5.0.7.2 because that’s what we’re using at
work.