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The interview-prep guide that

actually sticks.

Most DSA courses feel like reading a math textbook in a noisy library.

This one feels like playing a game — one level a day, for thirty days.

Free forever · No signup · Bookmark and bail any time
30
Days, end-to-end
150+
Hand-picked problems
3
Languages — C++, Py, Java
0
Paywalls, ever

SOUND FAMILIAR?

You’ve studied DSA. You still can’t do it.

You’ve watched 11 hours of YouTube on recursion and still freeze when an interviewer says “can you do it recursively?”

You’ve read the same Big-O cheat sheet six times. You still pause for two seconds before you say “logarithmic.”

You know what dynamic programming is. You still don’t trust yourself to pick it on a brand new problem.

Reading about DSA isn’t the same as doing DSA. This site forces the second one.

LIVE DEMO — NO SCROLL, GO

Don’t take our word for it.
Break the array yourself.

Push. Pop. Insert. Search. Every page on this site has a widget like this one — concepts you can poke instead of memorize.

Try it: Interactive Array
10
[0]
20
[1]
30
[2]
40
[3]
50
[4]
ONE-QUESTION POP QUIZ

Think you’ve already got the basics?

Prove it. One question. No login, no judgement, no shame.

What's the time complexity of accessing an element by index in an array?

Why this beats that other course you keep restarting

Six choices we made on purpose to keep you coming back tomorrow.

See it. Don’t memorize it.

Animated array shuffles. Step-by-step algorithm runners. Memory diagrams you can hover. The concepts that hide in textbook prose suddenly look obvious.

30 minutes. Not 30 hours.

Each day is one sit-down. No marathon. No “come back tomorrow when you’re fresh.” One topic, one walkthrough, one set of problems. Close the laptop. Repeat tomorrow.

Shaped like the interview.

The patterns FAANG actually asks. Solutions in C++, Python, and Java side-by-side. Difficulty badges so you know what you’re walking into.

Voice you can stand.

Opinionated. Occasionally funny. Allergic to academic hedging. Learning that doesn’t feel like a homework assignment from someone you don’t like.

No paywall. No signup.

Open the page. Read it. Close the tab. Skip a day. Come back in a month. It’s a book, not a SaaS — and the source is open on GitHub.

Built for tinkerers.

Every visualization is a live React component. Want to see what happens with a weird input? Type it in. The site bends to your curiosity.

Every day has the same four beats.

Predictable. Bingeable. Quietly addictive.

01
Intuition

An analogy. A diagram. The “wait, that’s it?” moment.

02
Visual walkthrough

Step through the algorithm. Pause. Rewind. Run it backwards.

03
Code in 3 langs

C++, Python, Java side-by-side. Pick your weapon.

04
Practice + quiz

Curated interview problems. Reveal solutions when you’re ready.

Open source on GitHub
No tracking, no ads
Updated as the curriculum evolves

The 30 days start whenever you click.

Not next Monday. Not after the holidays. Not when you “have more time.” Right now, one tab, no setup.

Begin Day 1

Free · Open source · Bookmark and bail any time