The new best way to master LeetCode fast is with this free & open source application

Hussain Ali — Mon, 21 Jul 2025 00:23:42 +0000

Back when I was preparing for software engineering technical interviews (and honestly, still preparing... does it ever really end?) I was using primarily Leetcode to practice. As most people do. But after using it for a while, I quickly realized that Leetcode was missing a lot of stuff, and that I found myself using more and more external tools (Excel spreadsheets, various AI models, Notion, physical notebooks, etc.) to keep track of everything and stay on pace. That led me to create Repcode, a free, open-source platform built specifically to help people master Leetcode-style interviews faster and more efficiently.

But what is Repcode?

Repcode is your intelligent notebook for Leetcode. It helps you organize, review, and get feedback on your coding practice so you don’t waste time spinning your wheels. It includes features like:

Custom Collections: Group problems by data structure, pattern, or topic. Think "Sliding Window", "Binary Search", etc.
Detailed Problem Tracking: Save notes, solutions, metadata, and get visual stats on how you're doing across patterns.
Spaced Repetition Review Mode: A built-in, customizable spaced repetition system (like Anki, but for Leetcode) ensures you revisit problems at the right time.
AI-Powered Feedback: Instantly check your solutions against the optimal ones. Find bugs, inefficiencies, or better approaches on the spot.
One-Click Autofill from Leetcode: Quickly log problems with metadata scraped directly from Leetcode.
Progress Visualization: Color bars, charts, and warnings to keep you honest and on track.

It’s not meant to replace Leetcode, but to supercharge it. Think of Leetcode as the textbook, and Repcode as your dynamic, personalized study notebook.

Tech stack

Frontend: React + Tailwind CSS
Backend: Node.js + Express
Database: PostgreSQL
Auth: Firebase Authentication
AI Integration: OpenAI API
Spaced Repetition Logic: Custom implementation inspired by Anki algorithms

How it's helped me, 2000+ users, and how it can help you too

Since launching, over 2000 users have used Repcode to build better habits and finally get consistent with their interview prep. I personally went from randomly solving problems with no direction to feeling confident in patterns, data structures, and knowing exactly what I had to work on each day.

Whether you're just starting out or in your final sprint before interviews, Repcode gives you a structured, intelligent way to actually retain what you're learning — not just grind aimlessly.

And did I mention it's all fully open source?

Yes, the entire platform is fully open source and available on GitHub. Contributions are welcome, and if you find it useful, please consider leaving a star 🌟—it helps a lot!

Hope you found this helpful, and happy coding! 🚀

DEV Community: Hussain Ali

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