Yes, this website. Seems simple, but I had to spend some good hours doing it (especially the dual language functionality lol)! It's a bread and butter, made with love using the Jekyll framework. I also had to learn the Liquid template engine & Markdown conversion tool.
What about finding the best Instagram gastronomy posts on a single map? On Mapa Paladar we can access our Instagram information, share our posts and view tasty gastronomy tips of our IG friends. It's a Ruby on Rails + Javascript web app, with Instagram, Google Maps and Google Places API's integrations.
A Ruby on Rails microservice API to organize contracts and request digital signatures using ClickSign.
Some JavaScript challenges.