Run the following to update brew, install elixir, yarn, etc. You should only need to run this once:

brew update
brew install elixir yarn
mix local.hex

Run the following to install/update Elixir dependencies:

mix deps.get

Run the following to install/update JavaScript dependencies:

cd assets && yarn install

Start the local development infrastructure:

docker-compose up -d

Run the database migrations for all OTP apps which have a database:

mix ecto.create
mix ecto.migrate

Run the Elixir tests for all apps:

mix test

Start all of the apps and run all of the servers:

mix phx.server

Visit http://localhost:4000 from the browser.

You can also use iex to launch an interactive Elixr REPL:

iex -S mix