This is a Phoenix Framework and Elixir application designed to provide real-time arrival times for buses in Porto, Portugal, specifically for the STCP (Sociedade de Transportes Colectivos do Porto) network.

Here are some screenshots of the app, and also a screenshot how the official page loads on mobile (for comparison). It works but is very hard to interact and read, that's why when I was in college I had this in my bucket list of things to do.

Main Page	Bus Stop Page	Official Page

I made this with LLM's and some manual intervention to test phoenix.new. It was a project that I had in my too do list since I was in college and I would ride these buses frequently. There was no mobile friendly website to check this out (there were apps but I did not want another app in my phone for something as simple as this).

The LLM struggled a lot with figuring out how to scrape the data from STCP website, because it populates it after the initial page render. It spent me more than $20 in tokens figuring this out. Then I gave up and found on Github a library that did that already and used it to feed to LLM, and finally it succeeded. You can check the API library here: https://github.com/mig4ng/stcp_api

I did some manual changes for it to include the bus line color in the name (similar to the official website).

There is a lot of improvement margin, but overall tools such as phoenix.new and devin.ai alongside with large language models are getting really useful. For now for very small, limited scope develpments.

https://stcp.carneiro.pt/

To start your Phoenix server:

• Run mix setup to install and setup dependencies
• Start Phoenix endpoint with mix phx.server or inside IEx with iex -S mix phx.server

Now you can visit localhost:4000 from your browser.