TraceCode

What it does

Grinding LeetCode teaches you to pattern-match memorized solutions, not to actually see how algorithms work. TraceCode is different, you step through real code, watch state change live, and do drills that make you predict what happens next. Fewer problems, deeper understanding, better interviews.

Learn algorithms through interactive visualization and guided practice.

Master algorithms by seeing them work. Write solutions to coding problems and trace every variable, pointer, and state change live from your code. Given an m by n grid, count how many unique paths reach the bottom-right corner. Input: m = 3, n = 4 Output: 10 Explanation: Each cell combines paths from top and left. Requirements • Initialize the first row and first column. • Fill each cell from its top and left neighbors. • Return the bottom-right table value. C++ 1 #include <vector> 2 3 class Solution { 4 public: 5 int uniquePaths(int m, int n) { 6 std::vector<std::vector<int>> dp(m, std::vector<int>(n, 0)); 7 for (int c = 0; c < n; c++) { 8 dp[0][c] = 1; 9 } 10 for (int r = 0; r < m; r++) {…from tracecode.app

• IM
  I made a spaced repetition tool to master coding problems2024 · lanki.xyz · ▲206

  As you solve LeetCode questions, you can mark them as hard, medium, or easy. The tool will then recommend questions you should review based on (1) how hard the question was for you and (2) how much time has passed since you last reviewed it. I'd recommend normally attempting LeetCode problems and just marking them as hard, medium, or easy for you at first so the tool knows which problems to recommend you review! Here's the theory behind spaced repetition and learning if interested: https:&#x2F;&#x2F;www.codecademy.com&#x2F;article&#x2F;spaced-repetition

• 
  LeetCode Interview2021 · leetcode.com · ▲70

  Online coding interview platform for professionals

• 
  Learn LLMs LeetCode Style2025 · github.com · ▲181

  LeetCode for PyTorch — 65 ML/AI interview problems from real interviews at Google, Meta, Anthropic. Jupyter notebooks, an auto-grader, and an MCP AI tutor. - Exorust/TorchLeet

• 
  LeetCode AppApr 2026 · leetcode.com · ▲73

  The best place to improve your coding skills for interviews.

• 
  LeetCode LearnDec 2025 · leetcode-learn.web.app

  Master algorithms. Interactive, offline, & gamified.

• 
  LeetTrainer — Crush CS Interviews2025 · ▲17

  Master LeetCode faster with instant AI feedback and hints

• 
  /dev/null▲490

  a social network for devs

  Dev tools · 4d ago · dev-null.sh

• 
  Run full iOS 16.5 firmware on Android Devices▲433

  Contribute to oosexgang/hackios-xnu-kernel development by creating an account on GitHub.

  Dev tools · 18h ago · github.com

• 
  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 29d ago · github.com

• 
  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 27d ago · github.com

• 
  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 24d ago · openbot.run

• 
  Talanoa▲346

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 22d ago · talanoa.email

• 
  Brila▲1,364

  One-page websites from real Google Maps reviews

  AI · Apr 2026 · brila.ai

• AG
  A game where you build a GPU▲964

  Thought the resources for GPU arch were lacking, so here we are

  Life & fun · Apr 2026 · jaso1024.com

• 
  I built a tiny LLM to demystify how language models work▲915

  Built a ~9M param LLM from scratch to understand how they actually work. Vanilla transformer, 60K synthetic conversations, ~130 lines of PyTorch. Trains in 5 min on a free Colab T4. The fish thinks the meaning of life is food. Fork it and swap the personality for your own character.

  AI · Apr 2026 · github.com

• 
  Fathom 3.0▲800

  AI meeting notes: now bot-free, in ChatGPT & Claude + more

  AI · Apr 2026 · fathom.ai

• 
  Brutalist Concrete Laptop Stand (2024)▲786

  I made a laptop stand out of solid concrete, in the style of brutalist architecture, with themes of urbex and urban decay

  Life & fun · Apr 2026 · sam-burns.com

• 
  I built a frontpage for personal blogs▲783

  With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https:&#x2F;&#x2F;text.blogosphere.app&#x2F; Non-minimal: https:&#x2F;&#x2F;blogosphere.app&#x2F; If you don't find your blog (or your favorite ones), please add them. I will review and approve it.

  AI · Apr 2026 · text.blogosphere.app