Built for working engineers

Stop reversing
binary trees.
Start engineering.

The only interview platform built around how software actually works — incidents, PR reviews, system failures, and real trade-offs.

Start Free — no card needed

Joined by 4,200+ engineers from Google, Stripe, Amazon, Vercel

terminal

$npm install -g engprep

✓ engprep installed (v2.1.0)

$engprep pull war-room-42

✓ Incident bundle downloaded → ./engprep/incidents/war-room-42/

GoogleStripeAmazonVercelShopifyCloudflareDatadogLinearDiscordFigmaNotionPlanetScaleGoogleStripeAmazonVercelShopifyCloudflareDatadogLinearDiscordFigmaNotionPlanetScale

The problem with LeetCode

You've been practicing the wrong thing.

LeetCodeWhat it tests

✗Reverse a linked list in O(n)

✗Find the kth largest element

✗Implement BFS from memory

✗Solve DP problems in 20 minutes

engprepWhat your job requires

✓Debug why checkout is failing for 12% of users

✓Review a PR that will cause a memory leak

✓Design a system that won't crash at 10M users

✓Own a P0 incident under real time pressure

Both matter. Only one of them actually gets you hired and makes you a better engineer.

Engineers enrolled

Real-world scenarios

Interview success rate

0mo

Avg. prep time saved

What you practice

Four modes. Zero toy problems.

Every mode mirrors a real interview or on-the-job scenario.

workspace — war-room

ENG-911: Checkout failure · 12% error rate · Redis hit rate 94% → 31% · Deploy at 14:28

Error Rate

12.4%

P99 Latency

2.4s

Cache Hits

31%

DB CPU

97%

[WARN] 14:31:02 · Cache eviction rate exceeded threshold

[ERROR] 14:31:45 · DB connection pool exhausted (512/512)

[FATAL] 14:31:57 · payment-processor-3: OOM killed

Mastery Codex

Defeat bugs. Collect creatures.

Every challenge you solve drops a creature into your Codex. Rare patterns unlock Legendary creatures. Your collection becomes a living record of your engineering depth.

Explore Codex →

🐉

Cache Hydra

Legendary

👻

N+1 Phantom

Rare

⚔

Concurrency Lord

Epic

🌀

Race Condition

Rare

💳

Webhook Phantom

Epic

🌩

Thunder Cache

Rare

🔮

Deadlock Specter

Uncommon

🦠

Memory Parasite

Common

31 creatures across 10 engineering archetypes

Weekly Raid — LIVE

847 engineers are
responding to a P0 right now.

Every Friday, a global P0 incident drops. Every engineer on the platform responds together. The fastest resolvers earn Legendary drops and XP bonuses.

847

Engineers in

37%

Solve rate

2d 23h

Time left

Join the Raid →

Global Payment Rail Meltdown⬤ LIVE

[P0] payment-processor: latency 34,212ms · 6 regions

[FATAL] pgbouncer: pool exhausted 14500/14500

[WARN] stripe-ingest: 14,832 webhook events / 60s

[ERROR] webhook-dispatcher: no concurrency limit set

Leaderboard

Engineering is competitive. Own it.

See full leaderboard →

Priya R.

41,200 XP

Siddharth G.

58,900 XP

Alex K.

33,400 XP

Career tracks

Built for where you are.
Designed for where you're going.

Entry level · 0–2 yrs

Junior

✓ Contextual DSA workspace
✓ PR review basics
✓ War Room Level 1
✓ Behavioral scenarios

Explore Track →

Mid level · 2–5 yrs

Mid

✓ Everything in Junior
✓ Architecture Autopsy
✓ System Design fundamentals
✓ Company-specific tracks

Explore Track →

Senior level · 5+ yrs

Senior

✓ Everything in Mid
✓ Tech Debt Tribunal
✓ Advanced system design
✓ Staff-level War Room scenarios

Explore Track →

Try it now

“Any AI can pass a coding test.
Only you can own the incident.”

[CRITICAL] 2026-04-03 14:31:22 · Payment Gateway Latency > 5000ms · $2.4M/hr revenue impact

A massive traffic spike hits your API. Database CPU is at 99%. P99 latency is failing checkouts. What is your first action?

A. Restart the database cluster

B. Enable the emergency request rate limiter

C. SSH into the primary db and run EXPLAIN on active queries

Practice full War Room scenarios →

What engineers say

Real quotes. No made-up testimonials.

Priya S.

SWE II → Staff · Stripe

𝕏

★★★★★

“I've failed 4 staff-level system design loops. After 3 weeks on engprep, I passed 3 in a row. The War Room scenarios are eerily close to what they actually ask.”

@priya_srini

Marcus T.

Senior SWE · Cloudflare

𝕏

★★★★★

“Finally. An interview tool that doesn't make me feel like I'm studying for a math competition. The War Room stuff is exactly what we ask in our senior loops.”

@backend_dev_nyc

Aisha L.

Mid → Senior · Shopify

𝕏

★★★★★

“I was failing System Design interviews for 3 months. engprep's simulator showed me WHERE my bottlenecks were instead of making me draw boxes on a whiteboard.”

@frontend_monk

Siddharth G.

SWE III · Google

𝕏

★★★★★

“The PR Review mode caught exactly the kind of bugs that show up in real code reviews. I felt prepared for actual work, not just whiteboard tricks.”

@siddharth_g_dev

Pricing

Simple. Honest. No dark patterns.

🌱 Free

Explore the platform

$0 forever

10 challenges (sampler set)
2 War Room attempts
10 Codex creatures
Streak tracking
Public profile & rank card

Start for free

Stop reversingbinary trees.Start engineering.

You've been practicing the wrong thing.

Four modes. Zero toy problems.

Defeat bugs. Collect creatures.

847 engineers areresponding to a P0 right now.

Engineering is competitive. Own it.

Built for where you are.Designed for where you're going.

“Any AI can pass a coding test.Only you can own the incident.”

Real quotes. No made-up testimonials.

Simple. Honest. No dark patterns.

Stop reversing
binary trees.
Start engineering.

847 engineers are
responding to a P0 right now.

Built for where you are.
Designed for where you're going.

“Any AI can pass a coding test.
Only you can own the incident.”