5K+ interactive labs · 10K+ problems & lessons
Don't just watch.
Build the engineer interviews want.
Design systems on a real whiteboard with AI-graded feedback, learn from lessons that move — and when it's grind time, a full coding judge is waiting.
- Problems & lessons
- 10K+
- Interactive labs
- 5K+
- Structured courses
- 100+
- Completed by learners
- 1M+
Problems & lessons
Interactive labs
Structured courses
Completed by learners
Interview simulator
Interviews are a skill. Train it.
100+ real system-design interviews — Design Twitter, Uber, YouTube — graded question by question, ending in a scored report of your gaps.
- A persistent whiteboard that autosaves as you design
- Phased questions, the way a real interviewer steers a loop
- AI rubric grading on every answer — what you hit, what you missed
- Calibrated to your target: Mid, Senior, or Staff
Guided sessions are live for System Design — AI Engineering and Low-Level Design sessions are next.
Start a guided session →Courses & labs
Lessons that move.
Reading about Raft is one thing. Killing a leader node and watching the election happen is another. Every CodePeet course is built from interactive labs and animations, not walls of text.
- 100+ structured courses across System Design, Low-Level Design, AI Engineering, SQL and DSA
- 5K+ hands-on labs built into lessons — simulate, break, and fix real systems
- 14 algorithm animators: step through arrays, trees, graphs, and DP frame by frame
- Code you can edit and run right inside the lesson — including live SQL
A few of the 5K+ labs: GPT tokenizers · Attention heatmaps · RAG debuggers · Raft leader elections · Consistent-hash rings · B-tree page splits
Browse the courses →And when it's grind time
Solve. Run. Get judged.
The classic coding grind, done properly — a real judge, not links to other sites. Write your solution, run it against hidden test cases, and earn the green Accepted.
- 4,005 problems, from your first array to Hard-level graphs
- 550+ runnable in-browser with hidden test cases and real verdicts
- SQL playground against a real e-commerce dataset — results as tables
- Submission history, difficulty filters, and company tags
Judge languages: Python · JavaScript · Java · C++
Browse problems →AI mentor
Hints first. Answers when you need them.
It knows the exact problem on your screen. At 2 a.m. before an onsite, that beats pasting into a chatbot.
And everything around it
A whole platform, not a feature list.
Progress analytics
Activity heatmap, streaks, badges, and per-topic skill bars.
Public profiles
A shareable page of everything you have solved and built.
Structured curriculums
100+ courses organized into guided tracks.
Your own curriculumsoon
Assemble courses into a private path that fits your goal.
Favorites & lists
Bookmark problems and build personal study lists.
Global search
Find any problem, course, or engineer in one box.
Community discussions
Compare approaches with voting and threaded replies.
Light & dark, everywhere
Every surface — editor and whiteboard included.
Built with its best learners
Get paid to make CodePeet better.
The deepest way to learn something is to teach it. Contributors write real content, experts review it, and the wallet pays out — referrals earn a 10% commission on top.
1. Contribute
Write problems, editorials, and lessons in a full visual editor.
2. Expert review
Every submission is reviewed before it ships — quality is the product.
3. Get paid
Accepted work earns real money — withdraw to UPI or bank.
Pricing
Start free. 80% of everything is.
No credit card, no trial clock. Upgrade only when the premium depth is what you need.
Free
80% of all content, open forever
- Thousands of open problems & lessons
- In-browser judge & SQL playground
- Progress tracking, streaks & profiles
- Community discussions
- AI mentor with daily hint quota
FAQ
Fair questions.
Is CodePeet really free?
Yes — 80% of all content is open without paying, including thousands of DSA problems, the in-browser judge, the SQL playground, progress analytics, and community discussions. Pro unlocks premium courses, complete sheets, and a much higher AI mentor quota.
Which languages does the judge support?
You can run and submit solutions in Python, JavaScript, Java, and C++ — with hidden test cases, real verdicts (Accepted, Wrong Answer, TLE…), and submission history. SQL runs against a real e-commerce dataset with results shown as tables.
How is the AI mentor different from ChatGPT?
It knows the exact problem you are working on, and it has two modes: Hint mode nudges your thinking without spoiling the answer, and Mentor mode explains in depth — so you learn the pattern instead of copying a solution.
What is the interview simulator?
Guided mock interviews on a real whiteboard: you pick a level (Mid, Senior, Staff), work through phased questions like Design Twitter or Design Uber, and an AI grades every answer against a rubric — ending in a scored report with your gaps and weak spots.
Can I contribute content and earn?
Yes. Approved contributors write problems, editorials, and lessons in a full visual editor; every submission is expert-reviewed, and accepted work earns money you can withdraw to UPI or a bank account. Referrals also earn a 10% commission.
Become the engineer who ships.
Your first graded practice session is five minutes away — the mentor is already waiting.