Welcome @manckaert!

Looks good to me. My main metric is whether I can read & understand it quickly, and I could.

mix format is your friend (although, like all friends, I have some disagreements from time to time). It’s good to get into the habit of using it - the community’s eyes are used to running over code formatted in a particular way. There’s only one block of code that got reorganised when I ran it:

    redirect_to =
      case location_header do
        {"Location", loc} -> loc
        nil -> nil
      end

If this becomes part of a bigger system, you may find passing tuples around gets confusing, in which case upgrade to a map or (better still) a struct.

Also, HTTPoison.get would, I imagine, be quite slow with lots of wait time. If you want to learn a bit more about the power of BEAM, you could have a crack at parallelising. I’m sure there are many articles explaining how - my google-fu turned up a reasonable one as a starting point: Write Unbelievably Clean Concurrent Code in Elixir Using the Task Module | TopTechSkills.com

Welcome @manckaert!

Additional to the comments written above, you could split the last function declaration:

# matches `foo,bar,foo` as the third argument should be the same as the first.  
# The `to_url` can be seen as an alias and makes the code easier to understand.
def verify_response({redirect_to, from_url, to_url = redirect_to}), do:
      %{result: :match, from_url: from_url, to_url: to_url}

# matches `foo,bar,baz`
def verify_response({redirect_to, from_url, to_url}), do:
      %{result: :no_match, from_url: from_url, to_url: to_url, redirect_to: redirect_to}

In your code, the function is quite small so it’s easy to digest. This is just to show you a technique you might not know already

Thank you @mindok for the welcome and taking a look!

You’re right about the formatting, I come from Python mostly and there black is a lifesaver - especially in a team. I was mostly relying on how Emacs formatted my code but I fixed and issue with elixir-ls and now the section you highlighted gets formatted correctly.

I had already started rewriting it using Tasks as I had already noticed the IO is killing performance when doing the HTTP requests. It’s turning out quite nice but currently the “result collection” is pretty messy

Thank you again for your time!

Thanks @BartOtten! I had thought of doing the verification like that as it feels more “elixir - like” but never got it working. Thanks for showing me the correct way