Ace your next engineering interview.With prep you'll actually remember.
Learn system design & DSA through real-life intuition, practice in an in-browser judge across four languages, and rehearse with a live AI interviewer that scores you like the real thing.
Keep a guest book at the door. As each guest arrives with number x, ask: “has someone with 9 - x already signed in?”
def twoSum(nums, target):
seen = {}
for i, n in enumerate(nums):
if target - n in seen:
return [seen[target - n], i]
seen[n] = iPrep for interviews at companies like
Most prep makes you memorize.We make it impossible to forget.
People forget algorithms. They never forget a good story. So every problem is taught the way it actually sticks — analogy first, then the mechanics, then the code.
Start with intuition
Every solution opens with a real-life analogy. You forget seen[target − n]. You never forget the guest book at the door.
Watch it run
Step through a worked example with a visual dry-run — see the data structure fill in, line by line, until the answer falls out.
Then write it for real
Implement it in the browser in Python, JavaScript, C++ or Go — and get an instant verdict from a real judge.
Three weeks later, you won't remember the exact code. You'll remember the guest book — and rebuild the code from it, live, in the room.
See it on a real problemEverything from first principles to the offer
No juggling a course site, a coding judge, and a mock-interview tool. It's all here, and it all talks to each other.
Learn
System design & DSA, taught so it sticks.
- Real-life intuition before any notation
- Visual dry-runs and multi-solution editorials
- Brute → better → optimal, with the trade-offs
Practice
Write code in the browser. Get judged instantly.
- Python, JavaScript, C++ and Go — zero setup
- Full test suites with instant accept / reject
- Study mode to read, code mode to solve
Interview
Rehearse live with an AI that scores you.
- Live mock interviews for system design & DSA
- Scored per dimension, like a real interviewer
- A readiness breakdown of what to work on next
Start with what works
Structured around what top-company interviews actually test.
Practice with an AI that thinks like a senior L7
Sit a real system-design or DSA round with an AI interviewer that adapts to your level, probes your trade-offs, and afterwards scores you on every dimension — architecture, scalability, communication — so you know exactly what to fix.
- Live feedback on your architecture decisions
- Identifies gaps in design coverage
- Scores communication clarity like a real interviewer
- Detailed post-session breakdown with improvement areas
Available now — one session free each month, unlimited on Pro.
AI Interviewer
Live session
Invest in your next offer
One Pro month costs less than a coding book. The offer it lands you doesn't.
Free
Try it. No credit card.
- Intro chapters across system design & DSA
- Unlimited in-browser coding (4 languages)
- 1 AI mock interview / month
- 3 AI complexity checks / month
- Progress, streaks & badges
- Full course library
- AI Coaching
- Company question banks
DSA
Master DSA, end to end.
- Everything in Free
- Every DSA course, fully unlocked
- Unlimited AI Coaching & complexity analysis
- Readiness, review & optimization insights
- DSA company question banks
- System design courses
- Included AI mock interviews
Add single system-design mocks any time from $9.
Pro
Everything — DSA + system design.
- Everything in DSA
- Every system design course & case study
- 6 AI mock interviews / month
- Per-dimension performance insights
- System design company question banks
- Priority support
Need more mocks? Top up with credit packs below.
Mock interview credits
Top up beyond your plan's monthly mocks. Credits are valid for 12 months.
$9
1 mock
$39
5 mocks
$79
12 mocks
Students save 40% with verification. · Prepping a team? Get in touch for group access.
Your next offer starts with one chapter.
Start free today — learn one pattern, solve one problem, and feel the difference when it actually sticks.
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