Coding interview practice tools
Tools for practicing coding and algorithm problems — AI hint coaches for LeetCode, spaced-repetition trackers, competitive coding battles, daily code puzzles, and learn-to-code tutors — aimed at interview candidates and programming learners.
Built for: Job-seeking developers and coding learners
Projects since May 04
110
Different builders
107
Last 4 weeks vs 8 before
▼ -42%
AI is the core
11%
Projects per week
Mostly web app (63%), browser extension (19%), game (4.5%) · from r/SideProject, r/chrome_extensions, r/vibecoding, r/IMadeThis
Latest
- LeetBook — Tracks accepted LeetCode submissions with pattern tags, AI-generated notes, filters, and stats in a Chrome side panel.“I was losing track of 300+ solved problems, so I built a Jira/ADO-style tracker for LeetCode (auto-capture + AI pattern tagging + notes)”
- onote — Attaches searchable notes to individual LeetCode and Codeforces problems.“chrome extension for taking notes on leetcode/codeforces questions”
- mindsolve — Aggregates solved coding problems from LeetCode and Codeforces into one dashboard and schedules spaced review of the saved code.“[Update] mindsolve - leetcode/codeforces import, google auth, new landing page”
- Whiteboard for LeetCode — Adds a saved whiteboard to LeetCode problem pages, with each board tied to its problem.“I built a Chrome extension that adds a whiteboard to every LeetCode problem”
- Mindsolve — Tracks solved coding problems, schedules spaced revision of them, and reports weak topics.“solved hundreds of leetcode problems and forgot most of them - so i built this”
- Buglyst — Provides a website for practicing debugging skills through hands-on exercises.“Trying a student-led debugging cohort in India (voluntary, unpaid)”
- BetterSWE — Delivers one short quiz question at a time on software engineering topics like system design, ML systems, and algorithms, with explanations and offline concept slides.“BetterSWE - a two-minute-a-day practice app for the AI and systems side of software engineering”
- CF Analytics Pro — Adds solved-rating charts, tag breakdowns, unsolved-problem tracking, bookmarks and submit auto-fill to Codeforces profile pages.“I built a browser extension that adds analytics to Codeforces profiles”
- PlayCloudLabs — Lets visitors try coding or technical challenges without an account and saves progress for signed-in users.“I built a platform where you can try challenges with signup — would love honest feedback”
- Helps users revise data structures and algorithms patterns for interview preparation.“Made a DSA revision platform for pattern memorizing and interview preparation”
- BotBlox — Lets kids build visual block puzzles that compile and run real Python or JavaScript code.“I built a visual Python/Javascript coding engine for kids, but I'm burning out. I'm looking to sell the complete IP and codebase.”
- Arclab — Teaches coding through lessons where users predict snippet output, write their own version, then compare against the actual result.“Testing a coding practice tool built around predicting code before running it, would love feedback”
- ForjaCero — Provides timed systems programming interview practice with a whiteboard, progressive hints, and C, C++, and Rust problems.“I built a low-level systems interview prep platform - looking for feedback”
- AlgoPath — Teaches algorithms through an ordered sequence of steps with self-written code, failing tests, and hint ladders, running in the browser.“I build Leetcode but better.”
- Shows a live leaderboard of users' solved problems and tracks daily practice across LeetCode, GFG, CodeChef and other DSA platforms.“Built a DSA leaderboard & grind tracker connecting LeetCode, GFG & CodeChef”
- Daily Coding — Gives everyone the same daily coding challenge and runs submitted solutions in a sandbox across 11 languages.“I got hooked on Advent of Code and wanted it all year, so I built a site that gives everyone the same coding challenge every day”
- Offers LeetCode-style practice problems for support engineering skills.“Need Help!”
- AlgoVault — Automatically syncs accepted LeetCode solutions to a user-selected GitHub repository using a repo-scoped token.“I built a privacy-first Chrome extension that syncs accepted LeetCode solutions to GitHub. Can you review the UX and permissions?”
- codewars-pretty-stats — Generates Codewars statistics as images for embedding in GitHub READMEs.“I created an open source API to get statistics from codewars to display on GitHub README”
- System Design Trainer — Teaches the 22 Gang-of-Four design patterns through hands-on Java coding exercises with automated tests inside VS Code.“I made a free VS Code extension that teaches all 22 GoF design patterns through real Java coding exercises (not quizzes)”
Most discussed
- Runs user code in Go, Java, or Python and shows its execution step by step as a visualization.“Algorithm visualizer watch your code run step by step”
- learncode.study — Offers a learning platform where users run code in Java, Python, JavaScript, and Rust.“Can anyone rate this website?”
- Quantum Odyssey — Teaches quantum computing through open-ended puzzle game levels where players build quantum circuits and watch algorithms unfold visually.“Took me a decade to make quantum computing something programmers can easily learn”
- Vibecoding for Students — Serves a step-by-step web tutorial that teaches students how to vibe code.“I had Sol build me a vibecoding tutorial for my students in one prompt”
- Learn Code — Teaches Python programming through skill paths, practice exercises, lessons, quizzes, and leetcode-style questions, running locally in Docker with sandboxed code execution.“I vibecoded something to help me (and you) learn how to actually code”
- grindmap — Lets users browse and filter LeetCode problems by the companies that reportedly ask them, with recency and sorting options.“Tired of paying for LeetCode Premium just to filter questions by company, so I built this”
- Nudge — Gives context-aware hints and guiding questions for coding problems instead of full solutions, with a side panel chat.“I’m a CS student and I finally launched my first Chrome extension!”
- stdoutle — Presents a daily code-output puzzle that players must answer correctly, with a roast for wrong guesses and leaderboard streak tracking.“I built a brain teaser game for devs”
- Screenshots coding interview questions and returns pattern breakdowns, step-by-step solutions, code, flowcharts, and complexity analysis, with voice Q&A.“Built my own interview assistant because the existing ones have outrageous pricing”
- Tabout for LeetCode — Lets users move focus out of the LeetCode code editor with the Tab key.“My chrome extension just hit 291 installs organically with no marketing!”