I Built the Tool I Wish I Had When Learning DSA

Rishu Roy — Sun, 14 Jun 2026 18:48:37 +0000

After failing 3 coding interviews, I realized the problem wasn't practice it was how I was practicing.

I spent 6 months grinding LeetCode before my first FAANG interview.

400+ problems solved. Every "Blind 75" problem is memorized. I felt ready.

Then the interviewer asked a sliding window variation I hadn't seen before. I froze. Drew a blank. Bombed the interview.

The problem wasn't that I hadn't practiced enough. The problem was that I had practiced incorrectly.

I memorized solutions instead of understanding patterns. I can recite code, but I struggle to adapt when problems change slightly.

So I built something different.

Introducing AlgoPatterns

A pattern-first DSA learning platform with visualizations that actually show you how algorithms work.

algopatterns.in

What Makes It Different

1. Pattern-First, Not Problem-First

Most platforms throw 2000+ problems at you and say, "Good Luck."

AlgoPatterns organizes everything around 17 core patterns:

Two Pointers
Sliding Window
Binary Search
BFS/DFS
Dynamic Programming
Backtracking
And 11 more...
Master the patterns, and you can solve any variation.

2. Visualizations That Actually Help

We have 50+ interactive visualizers that show algorithms step-by-step:

Watch two pointers converge in real-time
See the DP table fill cell by cell
Trace BFS spreading level by level
Visualize the call stack during recursion
Reading code is one thing. Seeing it executed is completely different.

3. Curated, Not Overwhelming

315 hand-picked problems organized by pattern.

Each problem includes:

Company tags (Google, Amazon, Meta, etc.)
Frequency indicators
Pattern classification
Difficulty rating
No more random grinding. Practice the right problems in the right order.

4. Real Code Templates

Every pattern comes with:

Java templates (copy-paste ready)
"When to use" indicators
Common mistakes to avoid
Key insights from each pattern

Who It's For

Interview preppers who want to learn patterns, not memorize solutions
CS students who find textbook explanations too abstract
Self-taught developers building DSA foundations
Visual learners who need to see algorithms, not just read them

What's Included

Free tier:

3 complete patterns (Sliding Window, Two Pointers, Binary Search)
All visualizers for free patterns
Progress tracking
Pro tier:

All 17 patterns
315 curated problems
All 50+ visualizers
Pattern cheat sheets
Priority updates

The Philosophy

I built AlgoPatterns with one belief:

Understanding beats memorization.

If you understand why sliding window works, you can solve any sliding window problem—even ones you've never seen.

If you just memorize solutions, you're gambling that the interview matches what you practiced.

Launch Offer

For launch week, use code LAUNCH30 for 30% off any Pro plan.

Try It Now

algopatterns.in

The free tier has no catch. Three complete patterns, all visualizers included.

See if the pattern-first approach clicks for you.

Built by an engineer who failed enough interviews to know what actually helps.

DEV Community: Rishu Roy

I Built the Tool I Wish I Had When Learning DSA