The Blind 75: Complete Guide and Optimal Study Order

Before the Blind 75 LeetCode list existed, interview preparation felt like an endless grind. Candidates would open LeetCode, sort by acceptance rate or company tag, and try to solve as many problems as possible. Some people attempted 300, 400, even 500 problems — and still felt unprepared walking into their interviews. The problem was never the quantity of practice. It was the lack of structure.

In 2018, a Facebook engineer posted a curated list of 75 LeetCode problems on the anonymous forum Blind. The post argued that these 75 problems, if studied carefully, would cover every major coding pattern you would encounter in a real technical interview. The list went viral almost immediately. Engineers who followed it started reporting better results with dramatically less time invested.

The Blind 75 proved a counterintuitive point: targeted, pattern-based practice beats raw volume every single time. Instead of solving hundreds of random problems, you could focus on 75 carefully selected ones that collectively span arrays, trees, graphs, dynamic programming, and every other category that matters. This guide walks you through the optimal way to study the Blind 75, how it compares to newer alternatives like NeetCode 150 and Grind 75, and how to combine it with spaced repetition so you actually retain what you learn.

The Blind 75 is a curated set of 75 LeetCode problems designed to cover all 13 major coding interview patterns with the minimum number of problems. It was created by Yangshun Tay, a Facebook engineer, and originally shared as a post on the Blind app — a forum popular among tech workers for anonymous discussions about compensation, interviews, and company culture.

The genius of the Blind 75 list is its efficiency. Each problem was chosen not because it is frequently asked at a specific company, but because it represents a fundamental pattern. Solve Two Sum and you understand hash map lookups. Solve Merge Two Sorted Lists and you grasp linked list pointer manipulation. Solve Coin Change and you internalize the bottom-up dynamic programming framework. Every problem teaches a transferable skill.

The list spans 13 categories: Arrays and Hashing, Two Pointers, Sliding Window, Stack, Binary Search, Linked List, Trees, Tries, Heap and Priority Queue, Backtracking, Graphs, Dynamic Programming, Greedy, Intervals, and Math and Bit Manipulation. With just 75 problems across these categories, you build a mental toolkit that covers roughly 80 percent of what top tech companies test in their coding rounds.

Why 75? It is not an arbitrary number. It represents the minimum viable coverage — enough problems per category to recognize the pattern and its variations, without so many that you waste time on diminishing returns. The Blind 75 is the Pareto principle applied to interview prep: 20 percent of the problems give you 80 percent of the pattern coverage.

One of the most common mistakes with the Blind 75 is solving problems in list order or jumping randomly between categories. The optimal blind 75 study order builds foundational patterns first, then layers more complex techniques on top. Each category prepares you for the next one.

Start with Arrays and Hashing (9 problems). These are the foundation of nearly every other category. Problems like Two Sum, Contains Duplicate, and Group Anagrams teach you hash map usage, frequency counting, and array traversal — skills you will use in every subsequent category.

Move to Two Pointers (3 problems) next. Once you are comfortable with arrays, Two Pointers introduces the idea of converging iterators. Valid Palindrome, 3Sum, and Container With Most Water show you how to eliminate nested loops by moving pointers strategically.

Then tackle Sliding Window (2 problems). This builds directly on Two Pointers — instead of converging, you expand and contract a window. Best Time to Buy and Sell Stock and Longest Substring Without Repeating Characters are two of the most commonly asked interview problems across all companies.

The Blind 75 inspired two major successors: NeetCode 150 and Grind 75. Each has its strengths, and choosing between them depends on your timeline and experience level. Understanding the differences helps you pick the best leetcode problem list for your situation.

The original Blind 75 remains the gold standard for minimum viable preparation. If you have 4 to 6 weeks before your interviews and solid fundamentals in data structures, the Blind 75 gives you maximum pattern coverage in minimum time. It is lean by design — there are no redundant problems, and every single one teaches a distinct skill.

NeetCode 150 expands the Blind 75 to 150 problems by adding more practice within each category. The additional problems provide deeper coverage of edge cases and pattern variations. If you are comparing neetcode 150 vs blind 75, the key difference is depth: NeetCode 150 gives you two or three problems per pattern variation instead of one. Choose NeetCode 150 if you have 8 to 12 weeks and want to feel thoroughly prepared rather than just adequately covered.

Grind 75 takes a different approach entirely. Created by Yangshun Tay (the same person behind the original Blind 75), Grind 75 is a flexible, time-based study plan. You input how many hours per week you can study, and it generates a personalized problem sequence. The problems overlap significantly with the Blind 75, but the ordering adapts to your schedule. Choose Grind 75 if your available study time varies week to week.

Solving a Blind 75 problem is only half the work. The real value comes from how you study each problem after solving it. Most candidates make the mistake of checking off a problem the moment they get an accepted submission and never looking at it again. This approach leaves retention on the table.

For every problem, follow a structured review process. First, solve it yourself with a time limit — 20 minutes for easy, 30 for medium, 40 for hard. If you cannot solve it within the time limit, read the solution, understand the pattern, and then close the solution and implement it from scratch. Never copy-paste a solution and call it done.

After solving, identify the core pattern. Ask yourself: what category does this belong to? What makes this a two-pointer problem instead of a sliding window problem? Could the same technique apply to a different problem? Write a one-sentence summary of the pattern in your own words. This forces you to extract the transferable insight rather than memorize the specific solution.

Finally, schedule a review. Come back to the problem in 3 days and try to solve it again without looking at your previous solution. If you can solve it cleanly, extend the interval to 7 days, then 14 days. If you struggle, reset the interval. This is the core of spaced repetition, and it is what separates candidates who retain patterns for months from those who forget them in days.

The Blind 75 is only as effective as your study method. Many candidates complete all 75 problems and still struggle in interviews because they fell into common traps that undermine long-term retention and genuine pattern recognition.

The first mistake is solving problems in random order. Jumping from a graph problem to an array problem to a DP problem prevents you from building momentum within a category. When you solve three Two Pointer problems in a row, you start to see the pattern — the sorted input, the converging indices, the comparison logic. When you scatter them across weeks, each problem feels like a new challenge instead of a variation on a theme.

The second mistake is spending too long on a single problem. If you have been staring at a problem for over an hour without progress, you are not learning — you are suffering. There is no shame in reading the solution after your time limit expires. The goal is pattern acquisition, not proof of intelligence. Read the solution, understand it, and come back to it in a few days.

The third mistake — and the most damaging — is treating the Blind 75 as a checklist. Solving all 75 problems once without any review is significantly less effective than solving 40 problems with spaced repetition. Your brain forgets solutions within days if you do not reinforce them. A candidate who has solved 40 problems and reviewed each one three times will outperform a candidate who solved all 75 once.

Other common pitfalls include skipping easy problems (they build foundational pattern intuition), ignoring time and space complexity analysis (interviewers always ask about it), and not practicing verbal explanations (you need to explain your approach out loud during the actual interview).

The missing piece in most Blind 75 study plans is a systematic review process. You can solve every problem on the list, but without spaced repetition, you will forget the patterns faster than you learn new ones. Research on memory consistently shows that distributed practice with increasing intervals produces dramatically better retention than massed practice.

Spaced repetition works by reviewing material at strategically increasing intervals — right before you would forget it. Instead of reviewing a problem the day after you solve it (when you still remember everything), you wait 3 days. Then 7 days. Then 14 days. Each successful review strengthens the memory trace and extends the interval further. Each failed review shortens it, ensuring you spend more time on patterns you find difficult.

YeetCode flashcards are designed specifically for this workflow. After solving a Blind 75 problem, you can review the corresponding flashcard that tests whether you remember the core pattern, the optimal approach, and the key insight — without re-solving the entire problem from scratch. This makes review sessions fast (5 to 10 minutes per category) while still reinforcing the deep understanding you need.

The combination of the Blind 75 curated problem list with spaced repetition creates a study system that is both efficient and effective. You get the pattern coverage from the carefully selected problems, and you get the long-term retention from the review schedule. Candidates who use this approach consistently report feeling calmer and more confident in interviews because they are not relying on short-term memory — they have genuinely internalized the patterns.