After failing to get comfortable with Ash quickly and asking around on reddit I decided to start from scratch again. let’s read a book.

iex does NOT make modules available by itself.

if you run iex -S mix it will load the mix.exs file

The long (expanded) version of -S is simply:

“start”

So:

-S  ==  --start

What it literally means

iex -S mix phx.server means:

“Start IEx, and start the program mix phx.server inside it.”

exs files are scripts, so

• Executed immediately, top-to-bottom
• NOT compiled into modules (unless you define one inside)
• NOT cached
• Re-run every time

The default port of cowboy is 4000.