The latest articles on DEV Community by Anshul Saxena (@anshullsaxena). https://dev.to/anshullsaxena https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3933991%2F291a8eff-6893-43ad-b2f5-f5bc3ade463e.png https://dev.to/anshullsaxena en Anshul Saxena Fri, 15 May 2026 23:13:12 +0000 https://dev.to/anshullsaxena/i-built-a-free-open-source-leetcode-practice-app-heres-how-44al https://dev.to/anshullsaxena/i-built-a-free-open-source-leetcode-practice-app-heres-how-44al <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fcvdlwpck9d6elyi7fs1n.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fcvdlwpck9d6elyi7fs1n.png" alt=" " width="800" height="432"></a></p> <h2> The Problem </h2> <p>Preparing for coding interviews usually means juggling multiple tabs — LeetCode for problems, a spreadsheet for tracking, a separate code editor for practice. It's messy.</p> <h2> What I Built </h2> <p>I built <strong><a href="https://hopefuel.vercel.app" rel="noopener noreferrer">LeetPrep</a></strong> — a unified LeetCode practice platform that brings everything together in one place. Entirely free and <a href="https://github.com/anshull-saxena/LeetPrep" rel="noopener noreferrer">open source</a>.</p> <h3> Company-Wise Questions </h3> <p>Browse problems from <strong>100+ companies</strong> (Google, Amazon, Meta, Microsoft, Apple, Netflix, and more) sorted by frequency and difficulty. Filter by timeline — see what companies asked in the last 6 months vs 2 years.</p> <h3> Blind 75 / 150 / 300 Paths </h3> <p>Follow curated study paths with a clean UI. Filter by topic and difficulty. Track progress with checkboxes and a progress bar.</p> <h3> Built-in Code Editor </h3> <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fc27hq4wjsk82b87eqlby.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fc27hq4wjsk82b87eqlby.png" alt=" " width="800" height="432"></a></p> <p><strong>Monaco Editor</strong> (same engine as VS Code) with syntax highlighting, 8 languages, and <strong>in-browser execution</strong> for JavaScript and TypeScript. No backend needed — your code runs instantly in the browser.</p> <h3> Problem Descriptions </h3> <p>Click any question to see the full LeetCode problem description, example test cases, topic tags, and hints — all fetched live from LeetCode's GraphQL API.</p> <h3> Progress Sync </h3> <p>Sign in with Google and your progress syncs to <strong>Supabase</strong>. Local-first architecture — works offline, merges seamlessly when you reconnect.</p> <h2> Tech Stack </h2> <ul> <li> <strong>Next.js 15</strong> (App Router)</li> <li><strong>TypeScript</strong></li> <li><strong>Tailwind CSS</strong></li> <li><strong>Firebase Authentication</strong></li> <li> <strong>Supabase</strong> (progress persistence)</li> <li> <strong>Monaco Editor</strong> (code editing)</li> <li> <strong>Vercel</strong> (hosting)</li> </ul> <h2> What I Learned </h2> <ul> <li>LeetCode's GraphQL API is surprisingly accessible and well-structured</li> <li>Building a local-first sync architecture is harder than it looks — merge conflicts on a set of strings are simple, but the UX around sync status matters a lot</li> <li>Monaco Editor + Next.js requires dynamic imports with SSR disabled</li> <li>Using the Dev.to API is refreshingly straightforward</li> </ul> <h2> Try It </h2> <p>App: <a href="https://hopefuel.vercel.app" rel="noopener noreferrer">https://hopefuel.vercel.app</a><br> GitHub: <a href="https://github.com/anshull-saxena/LeetPrep" rel="noopener noreferrer">https://github.com/anshull-saxena/LeetPrep</a></p> <p>The entire project is open source (MIT). Contributions and feedback welcome!</p> leetcode opensource webdev javascript