Interactive DSA & Coding Interview Preparation
FaangPrep.Stop Memorizing.
Start Visualizing.
Crack YourFAANGInterview.
Learn DSA by stepping through algorithms one operation at a time, then drill the coding patterns interviews are built on. Built for engineers preparing for FAANG and product-company interviews.
187
Interactive Visualizers
107
Pattern Lessons
16
Coding Patterns
Interview preparation you work through, not read
FaangPrep is an interactive platform for data structures, algorithms and coding interview preparation. Instead of reading a finished solution and hoping it stays with you, you step through the algorithm yourself — one comparison, one pointer move, one recursive call at a time — with the code that produces each step highlighted beside it.
It is built for software engineers preparing for technical interviews at FAANG and other product companies, and for anyone who has solved a hundred problems and still freezes on the hundred-and-first. The material runs from complexity analysis and Big-O through every core data structure, into the recurring patterns interview questions are actually built on, and finishes with a curated sprint you can work day by day.
Every lesson ships in JavaScript, Python, Java and C++. Starter lessons in each topic are free to open, and the full library is a one-time payment with lifetime access — there is no subscription.
Featured Courses
Expert-curated courses with interactive visualizations designed to help you crack FAANG interviews with confidence.
From confused to confident, in order
Most people fail interviews because they practise randomly. This is the sequence we recommend — start free, and only pay when you know it works for you.
01
See it before you code it
Start with 187 interactive visualizers. Step through recursion, graphs and DP frame by frame until the mechanism is obvious rather than memorised.
02
Learn the 16 patterns
Almost every interview question is a variation on a pattern. Sliding Window, Two Pointers, Monotonic Stack, DP — learn the shape once and recognise it under pressure.
03
Drill the 75 that matter
A curated sprint with a day-by-day plan and progress tracking. Choose a 2, 4 or 6 week cadence and stop guessing what to solve next.
04
Walk in ready
Tailor your resume to the role with AI, then rehearse the patterns you are weakest on. Preparation ends when recall is automatic.
Three ways in, one path through
Where you start depends on where you are. The three surfaces below are the same material organised for different stages of preparation, and they link into each other throughout.
Learn DSA by watching algorithms run
Sorting, searching, trees, graphs, hashing, dynamic programming, greedy, backtracking and advanced structures like segment trees and tries. Each lesson gives you a visualizer you control rather than an animation you watch — step forward, reset, change the input, and check your prediction against what actually happens.
Browse the full curriculum in the 187 interactive DSA visualizers.
Master the 16 coding interview patterns
Interview questions are variations on a small set of techniques: sliding window, two pointers, binary search on the answer, monotonic stack, top-K with a heap, BFS and DFS, backtracking, dynamic programming. The hard part is recognising which one a new problem wants — so every pattern covers how to spot it, what it costs, and the problems where you can watch it work.
Start with the coding interview pattern library.
Work a curated sprint, not a random problem list
A hand-picked set of 75 interview problems organised across 16 patterns, with a day-by-day study plan, progress tracking and streaks. Every problem connects back to the pattern it belongs to and the visualizer that explains it, so a problem you cannot solve has somewhere to send you.
See the plan in the DSA 75 interview sprint.
Built for understanding, not for grinding
You can memorise a solution and still freeze when the interviewer changes one constraint. Everything here is designed so that does not happen.
Watch the algorithm run
Static diagrams show you the answer. Our 187 visualizers show you the process — step forward, step back, change the input and watch what breaks.
Patterns, not problem counts
Grinding 500 random problems teaches 500 answers. Learning 15 patterns teaches you to recognise the shape of a question you have never seen.
A plan, not a playlist
The sprint tells you exactly what to do today. Pick a 2, 4 or 6 week cadence and track progress and streaks as you go.
Try the depth before you pay
The visualizers are free and open — no account, no card. Judge the quality yourself, then decide whether the paid paths are worth it.
Pay once, keep it
One-time payment with lifetime access. No subscription quietly renewing, no content disappearing when a billing period ends.
Upgrade without paying twice
Bought a single course and want everything? You pay the difference, not the full price — what you already spent is credited automatically.
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Why top engineers choose Faangprep
Interactive Execution
Don't just read static text. Control the flow, pause, rewind, and step through complex algorithms yourself.
Expert Curriculum
Built around the 16 patterns that recur across real interview questions — not a random problem list.
Code & Complexity
Real-time code highlighting and Big-O analysis.
Lifetime Access
Pay once, access forever. Includes all future updates and new courses.
Answers before you ask
What can I try before paying?
All 187 interactive visualizers are free, with no account and no card required. 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 — 107 lessons across 16 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.
Start with the free visualizers
No account, no card, no trial timer. Work through the visualizers, and if the way we explain things clicks, the paid paths are there.
One-time payment, lifetime access
Upgrade later, pay only the difference
187 visualizers free to try first
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