Spaced repetition for LeetCode

Solve it once. Still know it in the interview.

Patternwell watches your solves, rates them on what actually happened, and brings each problem back right before you'd forget it.

Start free Try a sample review Free for your first 150 problems. Get the extension for Chrome, Brave or Edge.
Why you blank in interviews

You don't forget at random. You forget on a curve.

That problem you solved last month? It's already slipping. Patternwell brings it back right before you'd forget, and every review makes it stick longer.

One problem, 60 days
Solved once, never revisitedWith Patternwell

Illustration of the standard forgetting model. Move across the chart to read any day.

01 · TIMED

Back right before you'd forget.

Every problem gets its own forecast. No fixed calendar, no guessing.

02 · COMPOUNDING

Each review buys more time.

Most take 90 seconds, and the gaps keep growing.

2 days→6→15→40+
03 · HONEST

Rated on what really happened.

Hints, wrong submissions and time all count. No lucky "Easy".

See it run

Every pattern leaves a shape.

Watch the code run, line by line. Each step adds a row, and the rows draw the pattern you'll spot in your next problem.

Python · C++ · Java · JSGuess the next stepAll 24 patterns hover to rewind · tap for a new example

Other revision tools trust the button you press. Patternwell checks it against the hints you opened, your wrong submissions and the time you took. So the schedule follows what you really remember.

01 · Every morning

One short list. Then you're done.

Open the extension and see exactly what's due and how long it takes. Set a daily limit and the list never grows past it.

02 · Quick reviews

Most reviews take 90 seconds, not 40 minutes.

You get a short description in our words with the title hidden. Name the pattern and the complexity, then check. Full re-solves come only when they matter.

03 · Pattern memory

Interviews test patterns. So does Patternwell.

It knows how well you remember each of 24 patterns, not just each problem. A fading pattern gets a short drill before it slips.

04 · Interview day

A handful of reviews keeps a problem for months.

Without review, memory fades. Each well-timed review resets it and buys more time. Tell Patternwell your interview date and it plans for that week.

The engine

An engine that does the remembering for you.

A memory model trained on hundreds of millions of real reviews forecasts when you'll forget each problem. On top sits our own layer that thinks in patterns and checks every rating. We tested it the hard way.

5.6×

Fresher patterns. In a 90-day simulation of the roadmap, no pattern went more than 12 days without being coded. Scheduling problems one by one let some drift for 67 days. Same time per day.

400/400

Exact maths. Our scheduler matched the published reference on all 400 test cases, agreeing to 14 decimal places.

92.4%

More kept on busy days. With only 8 reviews a day, Patternwell held 92.4% of the whole deck.

Grounded in research

Spacing and retrieval practice are among the best-replicated results in learning science (Cepeda et al., 2008; Latimier et al., 2021).

Learns you

After 400 reviews, the scheduler can be fitted to your own memory, and it only switches if the fit predicts you better.

Checkable

Stats show predicted recall against what really happened, so you never have to take our word for it.

What it does

Reminders tell you when. Patternwell checks what you remember.

  • Tracks your solves automatically
  • Schedule adapts to your memory
  • Rating checked against what happened
  • Memory per pattern, not just per problem
  • 90-second reviews with the title hidden
  • Solutions hidden while you re-solve
  • Planned around your interview date
Pricing

Free for your first 150 problems. Pro costs less than one coffee a month.

₹25 a month on the yearly plan. A café coffee is gone in ten minutes; this keeps every problem you've solved ready for the interview that matters.

Free
₹0
Free everywhere
  • Revision for up to 150 problems (more are saved, not scheduled)
  • Honest ratings and quick reviews
  • Daily limit and 4-week forecast
  • 10 drills a week
Start free
Pro yearly Coming soon
₹300/ year
$12 outside India
  • Unlimited problems
  • Re-solve mode with solutions hidden
  • Timed interview mode
  • Unlimited drills
  • Interview-date planning
  • Paid once for the year · no automatic renewal
Coming soon
Pro monthly Coming soon
₹50/ 30 days
$2 outside India
  • Everything in Pro
  • For the last weeks before interviews
  • Doesn't renew by itself
Coming soon
Pay with
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Checkout by Razorpay

Pro opens soon. Start free today: everything you review now carries straight over. When it opens: full refund within 7 days, no questions asked, and a founding lifetime of ₹999 ($29) once for the first 200 people.

Why this exists

I kept re-solving problems I'd "done" months earlier and still blanking. The tools I tried let me rate a solve Easy right after reading the editorial. Patternwell is the revision system I built for my own prep, made honest enough to trust.

Questions

Before you install

Does it read my code?

No. It only notices that you submitted, the verdict, the hints you opened, which tabs you visited and how long you were active.

I've already solved 200 problems.

Import them in one go. They're spread over the coming weeks so day one isn't a wall of reviews.

How does it know when I'll forget?

A memory model trained on hundreds of millions of real reviews gives every problem its own forecast. After 400 of your reviews, it can tune itself to how you remember.

Is this made by LeetCode?

No. Patternwell is independent and works alongside it. Quick reviews use descriptions we write ourselves, never LeetCode's text.

Stop re-learning what you already learned.

Start free