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NewThe curated path
Stop grinding random problems. Follow a path.
Everything a CS degree teaches you about DSA and system design, delivered the way a degree never does: one concept at a time, in two ordered courses. Each unit takes you the whole way, from never having seen the idea to spotting it in a problem you have never met.
1
Learn the concept
Short lessons with a checkpoint after every idea. You predict first, then find out, so it actually sticks.
2
Drill it
Quick applied scenarios lock the concept in before you ever touch code.
3
Pass the graded test
Prove you have it. Clear the unit, then move on with confidence instead of a vague feeling.
4
Solve real problems
Write and run real code, with the hints fading as you go, until you barely need them.
5
Recognize it cold
A final challenge with the pattern label stripped, the exact skill an interview tests.
One DSA unit, start to finish
Every unit in both courses runs this same loop.
Live demo · no account needed
Try it right now
This is the real product. Walk through Two Sum the same way every problem works.
“Can't I just ask ChatGPT?”
You can. But ChatGPT is happy to hand over the full answer, which is exactly what gets you stuck. It's a great crutch, not a great teacher. The whole point of DSA Trainer is the scaffolding around the answer.
How a problem flows
Every problem follows the same skeleton. You learn the skeleton once, and every future problem becomes a fill-in-the-blank instead of a blank page.
1
Understand the problem
Plain-English summary, sample input/output. No jargon dumping.
2
Spot the pattern
A one-line trigger question for each pattern so you start recognizing them on your own.
3
Review the brute force
See the naive approach and exactly why it's too slow, so the optimization feels necessary, not arbitrary.
4
Climb the hint ladder
Five rungs from nudge → near-solution. You ask for the next rung only if you need it.
5
Dry run, then code
Walk through state row by row before writing code, so you actually understand the trace.
Pattern ID Drills
The skill nobody trains: recognizing patterns cold.
You watch a solution video, understand every step, feel like you get it, then open the next problem and go completely blank. That is not a retention problem. It is a recognition problem.
Most practice is near-transfer: you apply Hash Map when someone tells you it is a Hash Map problem. Real interviews give you a cold problem description and expect you to figure that out yourself. That gap is where people fail, and almost no tool trains it.
Pattern ID Drills show you raw problem descriptions reframed in real-world scenarios, with all labels removed. Your only job is to identify the pattern. A scored session of 5 or 10 drills shows you exactly where your recognition breaks down.
How a session works
1
Read the scenario
A real-world problem description with no pattern label and no hints. Framed as something you'd actually hear in an interview, not the LeetCode prompt you may have memorized.
2
Pick the pattern
Choose from all 33 patterns. No process of elimination, no hints. You have to reason about the structure of the problem the same way you would sitting across from an interviewer.
3
See the diagnostic signals
Right or wrong, the reveal shows you the 3 to 4 signals that should have triggered the pattern. Next time you see those signals, you'll know what they mean.
After the session
Your score card shows which patterns you missed and links directly to the guided problem for each one. Work the problem, then run the drill again. That loop is how recognition becomes automatic.
33 patterns, each with a full guide
Every pattern includes a mental model, trigger questions, when to use it and when not to, and a full code walkthrough so you understand the pattern, not just one problem that happens to use it.
From the community
B
Big_Wolverine_7575Founding Member
Highly recommend this.
LeetCode never clicked for me. I took DSA in college, tried CTCI, NeetCode, YouTube videos, bought courses, and honestly tried really hard over the years, but still couldn't solve Two Sum. I'm ~4 YOE and getting back into interviews. I do well when I can talk about building and delivering real features/projects, but if I get asked a LeetCode question… nope.
This app finally made it click. It teaches the thinking process in a way that actually makes sense. The beginner mental models for the patterns are genuinely so helpful. App is set up really well and easy to follow. Super informative and fun to practice.
THANK YOU.
Left unprompted on Reddit, May 2026
DSA Trainer is a genuinely useful platform if you are trying to build consistency in your DSA prep. The structure is practical and focused, especially for tracking progress and staying disciplined with problem-solving.
And the spot-the-bug feature is crazy. I loved it.
Shared by DM, July 2026
vs. the alternatives
How DSA Trainer compares to LeetCode, NeetCode,
AlgoExpert, and AlgoCademy
Every platform has a target user. LeetCode is built for engineers who already know the patterns. NeetCode and AlgoExpert are built for people who learn from watching. AlgoCademy is built around AI that answers questions on demand. DSA Trainer is built for the person none of those serve well: someone who can build software but freezes the moment an algorithm problem appears.
DSA Trainer vs LeetCode
The industry standard, built for engineers who already know the patterns.
LeetCode: $159 / yr
✕
3,000+ problems with no guidance, no hints, and no structured path. Overwhelming for beginners by design.
Full comparison →
DSA Trainer vs NeetCode
The best free roadmap on the internet. But watching a solution isn't the same as solving one.
NeetCode: Free / $99 yr
✕
Video-first means passive absorption. You understand the video, then go blank on the next problem.
Full comparison →
DSA Trainer vs AlgoExpert
Polished and curated, but at 5-7x the price, still no hint system.
AlgoExpert: $160–200 / yr
✕
Slick videos without structured hints. You're either solving it alone or watching the full answer. And system design (SystemsExpert) is a separate purchase on top.
Full comparison →
DSA Trainer vs AlgoCademy
AI coaching that answers anything on demand, which is exactly the problem.
AlgoCademy: $299–399 / yr
✕
On-demand AI skips productive struggle. When the answer is one message away, you stop struggling, and struggling is where the learning happens.
Full comparison →
DSA Trainer: $49 / year, or $9 / month
Less than a single month of AlgoExpert or AlgoCademy, with DSA and system design in one subscription. The free tier has 4 full course units and 5 guided problems, no account needed.
Start free. Unlock everything when you're ready.
Big-O and Hash Maps are free to start, no account needed. One subscription unlocks both full courses, every guided problem, and the pattern drills.
- ✓Big-O Notation & Hash Maps: 2 full course units
- ✓Lessons, applied drills & graded tests
- ✓5 guided problems with the full hint ladder
- ✓JS + Python in-browser runner
- ✓Account progress that saves where you left off
Full access · both courses
Everything free, plus
Now includes a C++ runner alongside JavaScript and Python.
LeetCode Premium is $159/year and doesn't teach you anything.
Less than one Udemy course, with 150 guided problems instead of passive lectures.
One extra month of job searching costs more than a full year here.
- ✓The full 17-unit DSA learning path
- ✓System Design course: 20 building-block units
- ✓Concept lessons, graded tests & cold-read capstones
- ✓All 150 guided problems
- ✓52 Pattern ID Drills with scored sessions
- ✓New problems and units added every week
- ✓Direct feature request form
- ✓Cancel anytime
Cancel anytime. Not useful within 7 days? Email for a full refund. Secured by Stripe.
Frequently asked questions
Everything people ask before getting started. Tap a question to expand it.
What is DSA Trainer?
DSA Trainer is a guided learning path for people who can code but freeze on algorithm problems. It pairs two structured courses, one for DSA and one for System Design, with guided LeetCode-style practice that walks you through every problem in eight steps using progressive hints, so you build real pattern intuition instead of memorizing answers.
What is the Foundations learning path?
It's a structured course that takes you from the fundamentals (Big-O, hash maps, two pointers) all the way to interview-ready. Each unit teaches one concept, drills it with quick checks, ends in a graded test, then hands you real problems to solve with fading hints, and finishes with a cold-read challenge where the pattern label is hidden, the exact skill an interview tests. Big-O and Hash Maps are completely free.
Is DSA Trainer free?
Yes. The Big-O and Hash Maps units of the DSA path are completely free, including their lessons, drills, graded tests, and 5 guided problems (Two Sum, Contains Duplicate, Valid Anagram, Valid Palindrome, and Valid Parentheses), no account required. The first 2 System Design units are fully free too; the rest of the System Design course is premium. The full paths plus the library of 150+ problems across 33 patterns are on a paid plan: $9 per month or $49 per year.
Does DSA Trainer teach system design?
Yes. Alongside the DSA path there is a full System Design Foundations course: 20 building-block units (caching, load balancing, sharding, message queues, and more) taught through when-to-use judgment instead of reference diagrams, in the same prediction-first lesson format as the DSA path. The first 2 units are free.
Who is DSA Trainer for?
It's built for bootcamp graduates, CS students, and self-taught developers preparing for technical interviews, the people who understand a solution video and then go blank on the next problem. It's not aimed at competitive programmers; it's for building the foundational pattern recognition that interviews test.
How is DSA Trainer different from LeetCode?
LeetCode gives you the problem and a discussion tab; when you're stuck, your options are usually to watch the full solution or stay stuck. DSA Trainer never dumps the answer. It gives a progressive hint ladder, names the trigger that tells you which pattern applies, and walks a dry run row by row, so you learn how to think through the problem rather than memorize one solution.
Can I write and run code in DSA Trainer?
Yes. Every problem includes an in-browser editor where you can write and run JavaScript or Python against real test cases, so you can verify your solution without leaving the page.
How much does DSA Trainer cost?
DSA Trainer is $9 per month or $49 per year (subject to change). For comparison, LeetCode Premium is about $159 per year.