Shelly CLI

our mascot, shelly the turtle!

Inspiration

The inspiration behind this application came from the struggles we encountered when approaching programming and preparing for technical interviews. It’s hard to know where to start with data structures and algorithms. Everything feels abstract, and it’s unclear when to use what. So, we came up with an app that teaches DSA fundamentals through hands-on practice instead of passive learning or memorizing patterns from videos.

What it does

Shelly is an application that helps users master data structures and algorithms through real implementations, not word problems. It focuses on building a deep understanding of how each structure or algorithm works by having users implement them directly.

To test their work, users interact with a custom CLI tool we built, allowing them to use our commands, work in their own terminal, and get the authentic experience of coding on their machine. The CLI supports a guided curriculum that walks users through building complete data structures and algorithms from the ground up.

How we built it

We created a monorepo with three parts: React + Vite Frontend, the code testing CLI, and Supabase backend functionality (Auth, DB/Storage & edge functions).

Challenges we ran into

We had several low points when we realized that the goal we set of 6 languages and 8 data structures was too ambitious. We decided to ship 4 data structure modules with support for JavaScript, Python, and Java to ensure quality over quantity.

Accomplishments that we're proud of

We designed a clean, intuitive UX that makes learning feel warm and engaging. We’re especially proud of building our first-ever CLI tool with a robust GitHub integration. Most of all, we were all willing to step up when needed and worked very well as a team.

What we learned

We learned the importance of planning before writing a single line of code. In an age where AI can generate code instantly, the real value came from thinking through our architecture, understanding exactly what we were building, why we were building it, and how to balance staying within our scope while still pushing beyond it.

What's next for Shelly CLI

Our goal is to go beyond DSA and LeetCode prep. We want Shelly CLI to become a hands-on learning platform for everyone. Whether you’re a student, a newcomer to tech, or an instructor teaching through our labs, Shelly CLI will provide an interactive, project-driven curriculum designed to help users build confidence through real practice and fun problem-solving.