Hard interviews, explained simply

Become impossible not to hire.

1,200 interview questions ranked by how often they're asked, solutions you can watch run step by step, mock interviews and the lessons behind every answer. Practice until nothing in the room surprises you, and walk in as the candidate they can't ignore.

Start practicing free →See the roadmap

All core lessons freeNo credit cardNothing to install14-day money-back

~/your-journey

is this for me?

For anyone who wants the offer

New grad, experienced developer or career changer, anywhere in the world. Everything a hiring team checks, explained simply and in the right order.

Fresh CS grads

You have the degree. Now turn it into offers: the patterns, projects and interview practice that get you past every screen.

Developers chasing a better offer

Sharpen algorithms, system design and behavioral stories fast, then negotiate the offer you deserve.

Career changers

Bring your past experience with you. Everything a hiring team checks for, in order, and how to tell your story.

Anyone, anywhere

Software, frontend, backend or full-stack roles, at startups or big tech, in any country. Everything runs in your browser.

Want to learn computer science from the very beginning? Our sister site Crayon CS teaches the full CS curriculum, explained simply.

how it works

From “I hope I pass” to “they want me”

Find your gaps

Jump straight into interview questions, or start a course at your level. Skip what you already know.

Practice for real

Write real code in your browser. Tests tell you the second you've got it, just like an interview platform.

See every solution run

Step-through visuals show exactly what the code does, so you understand it, not just memorize it.

Walk in unshakeable

Timed mocks, model answers and STAR stories, so you explain your thinking clearly under pressure. That's what makes interviewers remember you.

Try the most-asked question →

the roadmap

Every skill interviews test, in one roadmap

11 courses, 92 lessons ready today and 121+ on the roadmap. Start at the beginning, or jump to the topic your next interview needs.

🎯 Interview Prep

1200+ questions: coding problems with tests, CS concepts and behavioral answers.

Browse questions

What you'll be ready for

Every round of the interview loop

Coding screens, system design, domain questions and behavioral rounds, at startups and big tech alike.

Coding interviews

Every pattern from hash maps to graphs and dynamic programming, ranked by how often it's asked.

System design

How apps serve millions of users, and how to lead a design interview with confidence.

Frontend & full-stack

JavaScript, React, browsers, APIs, databases and deployment: the questions web roles ask.

SQL & data

Joins, window functions and query design, practiced against a real database in your browser.

CS fundamentals

Memory, processes, networking and concurrency, explained clearly and tested the way interviewers do.

Behavioral & offers

STAR stories, big-tech values, salary talks and negotiation: the part most people under-prepare.

built for the AI era

AI writes code. Companies hire people who can judge it.

Every developer uses AI now. The ones who get hired can read what it wrote, spot when it's wrong, fix it, and explain their decisions. That takes real fundamentals, and that's what you'll build here.

Fundamentals deep enough to review AI output
A full course on working with AI like a pro
Find-the-bug exercises in AI-written code
Visual step-throughs so you understand code, not just copy it

ai-suggestion.js

// AI suggested this. Spot the bug?
function average(nums) {
  let total = 0;
  for (let i = 1; i < nums.length; i++) {
    total += nums[i];
  }
  return total / nums.length;
}

average([10, 20, 30]); // 16.67 ?!

pricing

Free to start. $39 a year for everything.

The core lessons and the most-asked questions in every topic are free. Everything else is one small payment a year: no monthly bills, and a tiny investment next to a new salary.

Free

Forever. No card needed.

The 10 most-asked questions in every interview topic
Core lessons: Python, SQL, frontend, full-stack, Git & more
Hands-on exercises, quizzes & step-through visuals
JavaScript, Python, SQL & HTML/CSS in your browser
Progress, XP, streaks & the playground

Start learning free

Everything included

Full access

$39/year

That's about 11¢ a day. One payment a year, no monthly bills.

Everything in Free, plus:
Advanced courses: algorithms, computer systems, system design
The full Interview Prep bank: 1,200 most-asked questions with visual solutions
New lessons every month

14-day money-back guarantee. Not for you? Email us within 14 days for a full refund. No questions asked.

Secure checkout by Stripe · One payment a year, no monthly charges · Turn off renewal anytime · Have a coupon code?
By subscribing you agree to our Terms and Refund Policy.

What candidates usually pay for interview prep

LeetCode Premium · Coding problems	$159/yr
NeetCode Pro · Video lessons	$119/yr
Exponent Pro · Behavioral & mock prep	$149/yr
Together	~~$427/yr~~
Crayon Interview Full access · coding, system design, behavioral & job hunt	$39/yr

Yearly list prices checked October 2026 (sources: LeetCode Premium, NeetCode Pro, Exponent Pro). Prices change, so check their sites.

Questions? Answered.

Who is this for?

Anyone who wants a coding job and wants to stand out in the interview: fresh CS grads, developers going after a better offer, and people switching into tech from another field. Everything you need to get hired is here, in order: interview questions, the lessons behind them, and the job-hunt skills.

I already know how to code. Is this too basic for me?

No. Skip the foundations and go straight to the 1,000-question interview bank, the algorithms course, system design and behavioral prep. Questions are ranked by how often they really come up, so your time goes where it counts.

I've never written code. Is this for me?

This site assumes you can already write basic code. If you're starting from the very beginning, our sister site Crayon CS (crayoncs.com) teaches the full computer science curriculum, explained simply. Come back when you're ready to job hunt.

Which jobs does it prepare me for?

Software engineer, frontend, backend, full-stack and data-adjacent roles, from startups to big tech. The bank covers algorithms, trees and graphs, JavaScript, Python, SQL, web, system design, CS fundamentals, tools and behavioral interviews.

Can this really get me ready for companies like Google or Microsoft?

It covers what those interviews test: data structures and algorithms, system design, CS fundamentals and behavioral questions built on their published values. Nobody can promise you a specific job, but you'll have practiced the right things in the right order, until you can solve and explain them with confidence.

What does "explained simply" mean? Is it basic?

No. The interview questions are the real, hard ones. "Explained simply" means every solution is broken down in plain words and visuals until it clicks, so you understand it well enough to handle a twist you've never seen.

How much time do I need?

20–30 minutes a day makes steady progress. If you have an interview next week, start with the most-asked questions in each topic: they're at the top of every list.

Is it really free?

Yes. Every core lesson and the most-asked questions in every topic are free. Full access ($39 a year) adds the advanced courses and the full interview bank.

What do I need to start?

Any laptop or desktop with a modern browser. Code runs in your browser, so there's nothing to install.

What if I get stuck?

Every exercise has hints and a full solution, and the visualizer steps through code line by line so you can see exactly where it goes wrong.

Can I cancel?

Anytime, from your dashboard, in two clicks. And there's a 14-day money-back guarantee if it's not for you.