FAANG interview preparation course
FaangPrep.Stop Memorizing.Start Visualizing.Crack Your FAANG Interview.
FAANG interview prep built on 105 interactive visualizers you step through yourself, plus the 17 patterns coding interviews are built on.
let l = 0, r = a.length - 1;while (l < r) { const sum = a[l] + a[r]; if (sum === t) return [l, r]; if (sum < t) l += 1; else r -= 1;interactive visualizers
interview patterns
pattern lessons
problems in the sprint
Start free. Pay once for the rest.
FaangPrep teaches data structures, algorithms and coding interview patterns to engineers preparing for FAANG and product-company interviews. Every visualizer is free — starter lessons with no account, the rest with a free account, never a card — and the paid courses are one-time purchases with lifetime access.
DSA Visualizer
All 105 visualizers across arrays, strings, sorting, trees, graphs, dynamic programming and advanced structures. Starter lessons open right now; the rest with a free account.
DSA Patterns
₹499
The full library
Learn the core patterns to solve any coding interview question.
Full Access Pass
₹999
Everything, including what ships next
Every course on the platform
Courses added later, at no extra cost
Four moves, every topic
From your first look at recursion to the question you get asked in the room. Five hundred random problems teaches you five hundred answers; this teaches you to recognise a question you have never seen.
Understand
What the structure is and what it costs, before any code.
Visualize
Step it forward and back. Change the input, watch what breaks.
Solve
Write it in one of 6 languages with the pattern in front of you.
Practice
Drill the sprint on a set cadence until recall is automatic.
All 17 patterns · 127 lessons
Browse the libraryJavaScript Interview Preparation
Master JavaScript fundamentals, tricky output-based questions, execution behavior, and essential interview concepts through interactive lessons.
Curriculum
50 Lessons Across 9 Categories
From variable scopes, closures, and prototypes to asynchronous microtasks, memory profiling, and modern ES6+.
Challenges
Interactive Output Prediction
Test your mental models against high-frequency ECMAScript edge cases and predict tricky console output before viewing the answer.
Runtime Engine
V8 Step-by-Step Execution Traces
Step forward and backward through code to watch the Call Stack, Lexical Scope, and Microtask queues update line by line.
No Paywall
100% Free Access
Every JavaScript lesson, quiz, code sandbox, and trace stepper is completely free with zero restrictions or mandatory login.
All 9 Topic Families · 50 Lessons
View Full RoadmapReact Interview Preparation
Master React fundamentals, Fiber reconciliation, state architecture, performance profiling, and FAANG machine-coding challenges through interactive lessons.
Curriculum
80 Lessons Across 16 Categories
Progressive beginner-to-advanced learning path from JSX and hooks to Fiber reconciliation, Concurrent React, SSR, and Server Components.
Output Prediction
Output & Lifecycle Traps
Master tricky state batching, stale closures, effect execution order, and key prop identity before inspecting step-by-step traces.
Live Coding
FAANG Machine-Coding Widgets
Build production-ready Autocomplete, Infinite Scroll, Tabs, Modals, and custom hooks with full WAI-ARIA accessibility and keyboard navigation.
No Paywall
100% Free Access
Every React lesson, interactive Fiber trace, quiz, and machine-coding challenge is completely free with zero restrictions or login walls.
All 16 Topic Families · 80 Lessons
View Full RoadmapNext.js Interview Preparation
App Router, React Server Components, caching and revalidation, Server Actions and production debugging, written around the questions frontend interviews ask.
Curriculum
72 Lessons Across 14 Categories
From CSR, SSR, SSG and ISR to the App Router, Server Components, data fetching, caching and Server Actions.
Architecture
Caching & Rendering Internals
The four cache layers, revalidateTag vs revalidatePath, static vs dynamic rendering, streaming and Partial Prerendering.
Interview Traps
Production Traps & Debugging
Hydration mismatches, stale router cache, redirect inside try/catch, middleware loops and the mistakes interviewers probe for.
No Paywall
100% Free Access
Every Next.js lesson, with its interview answer, code examples, common mistakes and FAQs, is free.
All 14 Topic Families · 72 Lessons
View Full RoadmapBefore you ask
What can I try before paying?
All 105 interactive visualizers are free. Starter lessons in every topic open with no account; the rest open with a free account, and no card is ever asked for. That is the bulk of the platform and the best way to judge whether the teaching style suits you. The pattern lessons and the DSA 75 sprint are the paid parts.
What is the difference between DSA 75 Sprint and Interview Preparation?
Interview Preparation is the full library — 127 lessons across 17 patterns. DSA 75 Sprint is a curated 75-problem path through that material with a day-by-day plan, progress tracking and streaks. Sprint is the structure; Interview Preparation is the depth. The Bundle is both.
If I buy one course now, do I pay full price to upgrade later?
No. Upgrades are credited automatically: you pay the difference, not the full price. If you buy the Sprint and later want Full Access, whatever you already paid is deducted. You are never charged twice for the same content.
What does Full Access include that the Bundle does not?
Full Access includes every course on the platform, including courses published after you buy — at no extra cost. The Bundle is a fixed pair of products. If you expect to want more than DSA, Full Access is the cheaper path over time.
Are there video lessons?
Not yet. Today the platform is written lessons plus interactive visualizers you control step by step — which for algorithms is often clearer than watching someone else scrub a timeline. Video walkthroughs are planned, and existing buyers will get them at no extra cost.
Do I need to be good at maths?
No. You need comfort with one programming language and a willingness to work through problems. Complexity analysis is taught from first principles inside the lessons rather than assumed.
How long does it take?
The sprint offers 2, 4 and 6 week cadences — roughly 2 hours a day, 1 hour a day, or 40 minutes a day. Pick honestly. Finishing a 6 week plan beats abandoning a 2 week one.
Get the interview, then pass it
Check your resume against a job description for free, then let AI tailor it. Built for software engineers, alongside the courses.
Free keyword check
Paste your resume and a job description and see which technical keywords you are missing. No account, and nothing leaves your browser.
AI tailoring
The AI rewrites your resume against the posting. Every edit is a diff you approve, with the match shown before and after.
Cover letters and outreach
Generate a cover letter and a recruiter message from the same job description, then edit them in place.
Clean PDF export
Four text-based templates, single- and two-column, in A4 or US Letter, with adjustable margins, spacing and fonts.
20% off every course
Register your email and we'll send you a coupon for 20% off all courses.
Start here
Open a visualizer.
Decide after that.
Free visualizers, no card, no trial timer. Judge the teaching yourself, and the paid paths are there from ₹299 when you want them.
One-time payment. Lifetime access. Upgrades credited.