Practice questions with real solutions, learn system design from structured tracks, rehearse with an AI interviewer, and keep a streak that actually holds you to it.
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System design: designing a rate limiter
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Most prep sites hand you a thousand problems and no order. CrackItt gives you a track, a solution you can actually learn from, and a habit that survives past week one.
Structured tracks take you from fundamentals to the questions that actually get asked, one lesson at a time.
Frontend internals, backend systems, databases, caching, and the infra questions that decide the senior loop.
200+
questions, lessons, and tutorials across every track — each with a solution, not just an answer key.
Check in daily. Consistency beats cramming the night before.
No dashboards to configure, no plan to pick. Start on step one today.
Frontend, backend, or full stack. Every track is a roadmap, not a random list — you always know what comes next.
Machine coding problems and interview questions, each with a worked solution, complexity analysis, and the trade-offs an interviewer will push on.
Implement a debounce function
It asks follow-ups based on what you actually said, then tells you where your answer was thin. Fail here instead of on the call.
Read write-ups from people who just sat the loop, ask the question you are embarrassed to google, and ship a project the reviewer will actually open.
What I got wrong in my Stripe onsite
12 min read · 148 upvotes
How deep do they go on event loop internals?
23 answers
Rate limiter with sliding window logs
★ 4.8 · 31 reviews
Designing a URL shortener, end to end
38 min video
Priya Raghavan
Frontend Engineer
Every question, solution, and lesson on this site came from someone who had just sat the interview. The best thing you can do for the next candidate is write down what you learned in yours.
Write a question
Add a problem you were actually asked, with a worked solution and the trade-offs an interviewer probes on.
See the content formatFix a bug
Issues tagged good first issue are scoped small on purpose — a single component, a single file, no context dump required.
Browse open issuesImprove the UI
Next.js 16, React 19, Tailwind 4. If a screen feels clumsy to use, that is a valid pull request on its own.
Read the web appNo issue that fits? Ask in the community and someone will point you at one.
Everything about the tracks, the AI interviewer, and how the prep actually works.
Yes, all of it. CrackItt is open source and free — the full question bank, both learning tracks, the AI mock interviewer, tutorials, community, and streaks. There is no paid tier and no trial to run out.
Frontend, backend, and full stack engineering interviews — coding rounds, machine coding, system design, and the behavioural questions that get asked alongside them.
You pick a track and difficulty, and the interviewer asks follow-up questions based on your actual answers instead of reading a script. At the end you get feedback on structure, depth, and the things you skipped.
Every question ships with a worked solution, complexity analysis, and the trade-offs an interviewer will probe. They are reviewed by engineers who have run these loops.
One question a day beats a panicked weekend. Checking in keeps your streak alive and your dashboard shows exactly what to review next.
Please do. Publish blogs, ask questions, and share projects in the community — good write-ups get surfaced on the dashboard feed. You can also send a pull request: new questions, solutions, bug fixes, and UI work are all welcome on GitHub.
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Start with one question today. Your future self, sitting in that interview, will be glad you did.
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