You found it first ⚡ 50% off any plan for 6 months, exclusive to new subscribers for a limited time only.
Join the Treehouse affiliate program and earn 25% recurring commission!
✨ Earn college credits in Cybersecurity, JS, HTML, CSS and Python
🌟 Dreaming of a bright future? 🎓 Ask about the Treehouse Scholarship program! 🚀
"Building Web Apps with Sinatra" was retired on June 1, 2025.
Code Challenges are the best way to test your knowlege. Sign up for Treehouse today and prove yourself. We guarantee 100% satisfaction.