1 · THE CHOICE
It picks the problems
Backed by memory research, not vibes.
- Spaced repetition decides what returns, and when
- New patterns arrive only when you're ready
- No lists, no study plan
PRIVATE BETA — WAITLIST OPEN
Stay interview-ready on one hour a day.
Pebble decides which problems you practise today — using the same memory science behind spaced repetition. You show up for your hour and do the work. That's it.
Science-based problem choice · Spaced repetition · Feynman technique
Today, chosen for you1 hour total
Quick warm-upfive short questions
5 minSliding Window Maximumnew, your weakest pattern right now
25 minCoin Changeyou got stuck on this 9 days ago
17 minRotated Arrayjust explain it out loud, no coding
10 minThis is the whole app: open it, do the list, close it.
The idea behind Pebble.
2 · THE DATA
Measured, not guessed
Your times and stumbles set tomorrow's list.
- Solve time vs. your own history
- Where you hesitated, not just pass/fail
- A recall score for every topic
3 · THE SIMPLICITY
One hour is the interface
Nothing to configure. Nothing to decide.
- 3-4 problems, sized to your hour
- Got 30 minutes? It re-cuts the list
- No streaks, no badges, no endless queue
THE GOAL
Be 80% interview-ready, permanently.
A level you hold all year on the smallest amount of daily time. When an interview appears, you're already most of the way there.
Less stress
Nothing rots, so there's nothing to cram.
More efficiency
Every minute goes where it counts today.
More variety
A different mix daily. Never a grind.
It stays
You keep what you solve.
Practising alone vs. practising with Pebble
On your own
- Twenty minutes gone just picking a problem.
- 200 solved, half unsolvable a month later.
- You redo your strengths, avoid your gaps.
- No idea if you'd pass next week.
With Pebble
- The list is waiting. Start in ten seconds.
- Problems return right before you'd forget them.
- Weak topics get the time. Strong ones step aside.
- A recall score per topic shows where you stand.
HOW IT WORKS
Four steps, every day.
Pick your hour
For example, 7 to 8pm on weekdays.
We make the list
3-4 problems that fit that hour exactly.
Solve or explain
Code the new ones. Talk through the rest.
Tomorrow adjusts
Nailed it? Later. Struggled? Sooner.
WHY AN HOUR IS ENOUGH
Some days you don't code. You just explain.
Re-typing a solved problem takes forty minutes. Saying how you'd solve it takes two, and tests the same understanding. That's how four problems fit in one hour.
YOU, 42 SECONDS“One half is always sorted at the midpoint, so I check which half that is, then decide whether the target can be inside it.”
HOW IT KNOWS
One number per topic: what you'd remember today.
Binary search92%
Two pointers88%
Graphs64%
Dynamic programming41%
Backtracking37%
WHO IT'S FOR
Anyone who's forgotten a problem they once solved.
Learn it once, keep it
Patterns in a sane order—still there at exam time.
Interview season, calmly
An hour a day beats cramming the week before.
Stay sharp on the side
One hour after work. Nothing to maintain.
Rebuild what faded
We start from what you remember, not zero.
Start with tomorrow's hour.
Free during the beta. Ten minutes to set up, then it plans every day for you.