How to Use LeetCode for Tech Interviews

If you’ve ever opened LeetCode and felt overwhelmed by thousands of problems, you’re not alone.

Most people approach LeetCode the wrong way:

• Random problems

• Long weekend sessions

• Memorising solutions

This isn’t a guide on how to “hack” interviews or memorise questions. The goal is to show you how to actually get better at problem solving — which is what interviews are testing.

Start with the basics

The most important thing is consistency.

Doing one hour every day is much better than doing seven hours once a week. You build pattern recognition over time, and that’s what actually matters in interviews.

Also, make sure you’re actively thinking while you practice. If you’re tired or not focused, it’s fine to stop and come back later.

Everyone learns differently, so treat this as a guideline, not a strict system.

Focus on the right problems

If you’re preparing for general software engineering roles, focus on algorithm problems.

LeetCode now includes things like databases and shell, but your main focus should be:

• Arrays

• Trees

• Graphs

• Dynamic programming

Use the algorithms problem set as your base.

Where to start

Don’t pick problems randomly.

A simple setup:

• Sort by difficulty: Easy → Medium → Hard

• Start with unsolved problems

• Prioritise problems with editorials

• Avoid low-quality problems (low upvote ratio)

Not all problems are equal. It’s much easier to learn from well-written ones.

You can skip questions if they feel too easy — the goal is to stay challenged, not bored.

The most important rule

Learn the pattern, not the problem.

This is the biggest difference between people who improve and people who don’t.

Instead of thinking:

“I solved this question”

Think:

“This is a sliding window problem”
“This is DFS on a tree”
“This is binary search”

If you only remember the problem, it won’t help you in interviews.
If you understand the pattern, you can apply it anywhere.

Suggested order

Work through topics in this order:

• Arrays

• Trees

• Recursion

• Graphs

• Dynamic programming

This helps you build up gradually instead of jumping into harder concepts too early.

What to do when you’re stuck

You will get stuck. That’s normal.

If you’ve been stuck for around an hour, don’t keep pushing blindly.

Instead:

• Read the editorial

• Check the Discuss section

• Look at other explanations online

Then go through the solution carefully:

• Understand each step

• Run it with your own example

• Make sure you understand why it works

The goal is not to “see the answer”, it’s to understand the idea behind it.

Don’t use the full problem set randomly

LeetCode has too many problems. You don’t need all of them.

Start with curated lists like:

• Blind 75

• NeetCode 150

• Grind 75

These cover the most important patterns without wasting time.

Only start doing random problems once your foundations are solid.

How to improve faster

Solving problems is not enough on its own.

Here are a few things that make a big difference:

Practice out loud

Get used to explaining your thinking while you code. This is exactly what you’ll do in interviews.

Find the optimal solution

If your solution works but isn’t optimal, go back and improve it.

Write down the pattern

After each problem, summarise it in your own words. This helps it stick.

Add time pressure later

Once you’re more comfortable:

• Try mock interviews

• Do weekly contests

This helps you get used to solving problems under pressure.

About LeetCode Premium

If you’re short on time, Premium can show company-specific questions.

This can be useful, but it shouldn’t replace proper preparation.

Your goal is still to build general problem-solving skills, not memorise specific questions.

Final thoughts

LeetCode works, but only if you use it properly.

The key ideas are simple:

• Be consistent

• Focus on patterns

• Learn from solutions

• Don’t rush the process

If you follow that, you’ll improve much faster — and interviews will feel a lot more manageable.

If you want to turn LeetCode practice into real interview performance, the next step is learning how to explain your thinking clearly.

Learn how to communicate your solutions in technical interviews →