Rehearse the interview
before you sit it.

Algorithms, system design, and timed mocks, until the real loop feels familiar.

45:00

Timed mock

45:00

Sliding window, hard

45:00 on the clock. No editorials until you stop.

Inside the library

Sliding windowConsistent hashingMonotonic stackWrite-ahead logsRaftBounded buffersUnion findRead replicasHappens-beforeRate limitersSegment treesCRDTsBackpressureBloom filtersIdempotency keysTopological sortChange data captureLock stripingSliding windowConsistent hashingMonotonic stackWrite-ahead logsRaftBounded buffersUnion findRead replicasHappens-beforeRate limitersSegment treesCRDTsBackpressureBloom filtersIdempotency keysTopological sortChange data captureLock striping

Five tracks

Everything a loop throws at you, in one place

The rounds you cannot bluff

Algorithms & data structures

Patterns first, problems second. Every solution ships with the reasoning that got there, not just working code.

Grouped by pattern — sliding window, monotonic stack, union find — so you stop re-deriving the same idea.
Complexity written out per approach, including the naive one you should mention and discard.
Follow-ups the interviewer usually asks after you finish.

Two pointersGraphsDPHeapsTries

problems: 1,284
patterns: 42
median time: 27m

Mock interviews

A rehearsal that argues back

Solving problems alone tells you what you know. A mock tells you what you can defend at minute thirty-eight with someone interrupting.

Timed solo mock

included

45 minutes, no interviewer. The clock, the prompt, and a written report the moment you stop.

report instant

Live engineer mock

2 / month on Interview+

A working senior engineer runs the round, pushes back mid-answer, and files notes the same day.

report within 24h

Next live slots open Thursday.

session replay · hld round

45:00

00:02

Interviewer

Design the feed for a link-sharing site. Ten million daily readers, writes are rare.

01:14

You

Read-heavy, so I'll fan out on write and keep a per-user timeline in a cache.

04:38

Report

Named the read/write ratio before choosing a strategy.

12:20

Interviewer

One account has four million followers. What breaks?

13:05

Report

Hot-key case handled, but you never said what happens while the cache warms.

Written report

7.9

Problem framing8.6

Trade-off depth7.9

Communication8.4

Time control6.8

You reached the right architecture nine minutes later than you needed to. Cut the API walkthrough — nobody scored it.

From the inbox

“The system design briefs are the first ones I've read that admit what the design gets wrong. Using it for my whole loop.”

Rayhan Hossain Rahat

Backend engineer, Dhaka

4.7

avg mock rating

2,910

reports delivered

Kept dropping system design knowledge until something finally stuck. The sharding brief alone was worth it.

Shubh Pathak

SDE II, fintech

@PathShubh

Booked a live mock on a Tuesday, had written notes by Wednesday morning. That turnaround is the whole product.

Joe Mifsud

Platform engineer, Malta

@Joe_Mifsud

I would have paid for this level of prep. Set up a tip jar already.

Sean Brydon

Full-stack, remote

@SeanBrydon13

Went in expecting another problem list. The pattern grouping is what actually changed how I solve things.

Tory Tang

New grad, SF

@torytang025

The capacity estimates are reproducible. Most resources hand you a number and move on.

Vlad Deifos

Staff engineer, Bucharest

@deifosv

The concurrency track is the only one I've found that makes you reproduce the deadlock before fixing it.

Ese Monday

Backend engineer, Lagos

@EseMonday1

My mock report told me I reached the right answer nine minutes late. Nobody had ever measured that for me.

Enis Kaya

SDE, Istanbul

@enisdev

Spent months looking for design practice that wasn't a video course. This is it.

Mark Vassilevskiy

Engineer, Tbilisi

@MarkKnd

I now send the behavioural worksheets to everyone on my team before their internal transfer interviews.

Tomiwa Adeyemi

Engineering manager, Lagos

@dnaijatechguy

The behavioural prompts force actual numbers out of you. Uncomfortable, and that's the point.

Greg Bergé

Open source maintainer

@gregberge_

Failed the same design round twice. Third attempt I had the read/write ratio out in the first two minutes.

Sreejith Kesavan

SDE I, Bengaluru

@Srejitk

The follow-up questions listed under each solution are the ones I actually got asked on-site.

Alex Chen

Senior engineer, Seattle

@alexchen_dev

Low-level design explained against query patterns instead of as a list of patterns. Rare.

Sarah Okonkwo

Tech lead, Berlin

@sarahcodes

Cut my prep from three months of scattered tabs to six focused weeks.

Miguel Rodrigues

Contractor, Lisbon

@mikerod_dev

Coding and design in the same tool, with the same reporting. I stopped juggling four subscriptions.

Emma Wilson

Infrastructure, Dublin

@emmawilson

The timed solo mock is brutal in the right way. No interviewer to nudge you back on track.

David Kim

SDE III, Toronto

@davidkim_ui

@rh_rahat_dev@PathShubh@Joe_Mifsud@SeanBrydon13@torytang025@deifosv@EseMonday1@enisdev@MarkKnd@dnaijatechguy@gregberge_@Srejitk@alexchen_dev@sarahcodes@mikerod_dev@emmawilson@davidkim_ui@rh_rahat_dev@PathShubh@Joe_Mifsud@SeanBrydon13@torytang025@deifosv@EseMonday1@enisdev@MarkKnd@dnaijatechguy@gregberge_@Srejitk@alexchen_dev@sarahcodes@mikerod_dev@emmawilson@davidkim_ui

Pricing

Cheaper than one missed offer

−21%

Pro

The full catalogue, plus the path through it

most picked

$14

/ month

billed monthly

Everything in Free, plus

Every track — algorithms, LLD, HLD, concurrency, behavioural
Unlimited timed solo mocks with written reports
A practice path rebuilt weekly from what you get wrong
Reference solutions in Java, Go and Python
Editorials that argue the trade-off, not just the answer
A spaced review queue for problems you lost
Company-tagged question sets
Progress export for your own tracker

“The report kept telling me I was losing rounds on trade-offs, not on code. Nobody had ever said that out loud.”

Priya Raghunathan — backend engineer, Kestrel Systems

cancel anytime30-day refundstudent rate −40%

No card required for the trial.

Free

no card

Enough to judge whether this is for you

$0

180 algorithm problems
10 system design briefs
Daily tech feed

Interview+

add-on

For a loop that is already booked

$39

/ month

Everything in Pro
2 live engineer mocks a month
Recorded sessions and same-day notes

Cancel from the account page in two clicks. Teams of five or more, email us for a shared plan.

Tech pulse

Something to say when they ask what you’ve read lately

The top of Hacker News, pulled every five minutes and stripped down to what an interviewer might actually bring up.

top stories

updated …

Questions

Answered without the click

Still stuck on something? hello@algorush.dev — a person replies, usually within a day.

01

What is AlgoRush exactly?

A practice library and a mock interview service in one place. The library covers algorithms, low- and high-level design, concurrency and behavioural rounds. The mocks put you under a clock and hand back a written report.

02

Where should I start?

Take one timed mock before reading anything. The report will point at the weakest track, and the practice path builds itself from there. Most people start with algorithms and are surprised it's design that costs them.

03

How deep does the system design material go?

Low-level design covers class models, schemas and API surfaces with reference implementations in Java, Go and Python. High-level covers capacity estimates, partitioning, replication and the failure story behind each choice — argued rather than listed.

04

Are the mock interviews with real people?

Both kinds exist. Timed solo mocks run against the clock with an automated report, and are included in Pro. Live mocks are run by working senior engineers and come with Interview+ — two a month, notes filed the same day.

05

How current is the content?

New problems land weekly and the tech feed refreshes every five minutes. Design briefs get revised when the underlying systems change, which happens more often than you'd hope.

06

What does it cost?

The free tier covers 180 problems and 10 design briefs with no card. Pro is $14 a month, or $11 billed yearly. Interview+ adds live mocks at $39. Cancel from the account page.

07

What if it doesn't help?

Email us inside 30 days and we refund the whole thing, including a month you've already used. We'd rather know why it didn't work.

08

Can a team use it together?

Yes — five seats or more get shared progress and a single invoice. Write to team@algorush.dev and we'll set it up manually for now.

Your next loop is already on the calendar

Start with one timed mock. It takes forty-five minutes and tells you more than a fortnight of reading.

Compare the plans

free tier · no card · 30-day refund on paid plans