It's not what you don't know.
It's what you're sure you know
and don't.
Explain a DSA concept out loud. CIP doesn't just check if you got it right — it catches the specific things you're confidently wrong about, before an interviewer does.
Free to start. No credit card.
Every other DSA tracker asks: right or wrong?
That misses the scariest failure mode — walking into an interview certain you understand something, and being wrong in a way that only surfaces under real pressure.
"A missing or incorrectly-placed base case just causes a slightly wrong answer."
A base case that's missing, unreachable, or checked after the recursive call causes infinite recursion and a stack overflow crash — not a "slightly wrong" answer. The base case must be checked before any recursive call, and the recursive case must shrink the input toward it on every call.
Three stages, one concept at a time
Deterministic code does the scoring, not a vibe check.
Explain it your way
Pick a concept and explain it in your own words — no multiple choice, no fill-in-the-blank.
Answer follow-up probes
CIP asks about whatever you left out or glossed over, the same way a real interviewer presses on a thin answer.
Solve a challenge task
A short problem that only works if you actually understood the concept, not just recognized its name.
Misconception is the headline. It's not the only signal.
Every session also tells you what's solid, what's shaky, and what you haven't covered at all.
13 topics, fundamentals to pro
From array indexing to bitmask DP and segment trees — 110 concepts total, each with its own prerequisites, common misconceptions, and practice problems.
Real questions, tagged by company
Every question comes with a hint ladder and a scoring rubric — these three are a sample of 69.
Partition Equal Subset Sum — determine if an array can be split into two subsets with equal sum.
Implement Trie (Prefix Tree) — design a trie with insert, search, and startsWith operations.
Cheapest Flights Within K Stops — find the cheapest price using at most k stops.
What's actually in here
Mock Interview Mode
69 questions across every topic in the platform, each with an opening prompt, a hint ladder, and a scoring rubric — run end to end like a real coding interview.
Company-tagged questions
Amazon, Google, Meta, Netflix, Microsoft, Apple, Uber, Bloomberg, Stripe, plus an Indian placement tier: TCS, Infosys, Wipro, Flipkart, Swiggy, Paytm.
Prerequisite graphs
Every topic renders as a real dependency graph, so you can see what to learn first instead of jumping in at random.
Built for long study sessions
Dark by default, with a light theme when you want it. Command palette (⌘K) to jump anywhere without reaching for the mouse.
Questions
How is this different from just doing LeetCode?
LeetCode tells you pass or fail on a test case. It can't tell you that you explained the recurrence wrong even though your code happened to work, or that you're one edge case away from a misconception you don't know you have. CIP is built specifically to catch that gap.
What if I don't know an answer at all?
That's the Missing state, and it's treated completely differently from a misconception. Missing means you haven't covered it — nothing to unlearn, just something to learn. Misconception means you actively believe something incorrect, which is a different (and more dangerous) problem to fix.
Does Mock Interview Mode cover behavioral rounds too?
Not yet — it's coding-questions-only right now. Behavioral question support is on the roadmap but not built.
Do I need to already be good at DSA to use this?
No — that's the point. The diagnostic works the same way whether you're starting from zero on a topic or think you've already mastered it. The Prerequisite graphs also show you what to learn first if you're starting fresh.
Is it free?
Free to use right now, no credit card required to start.