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Crack your
next interview.

Stop grinding generic LeetCode. Practice the real interview questions OpenAI, Anthropic and DeepMind actually ask — coding, system design, DL/LLM and classical ML, all in one place.

Real, reported questions from 26+ top labs & startups

self_attention.py
 1import numpy as np
 2# scaled dot-product attention
 3def attention(Q, K, V):
 4    d_k = Q.shape[-1]
 5    scores = Q @ K.T / np.sqrt(d_k)
 6    scores -= scores.max(-1, keepdims=True)
 7    w = np.exp(scores)
 8    w /= w.sum(-1, keepdims=True)
 9    return w @ V
pytest test_attention.py
output shape (8, 64)
attention rows sum to 1.0
matches torch reference
✓ 3 passed in 0.21s

Straight from real loops

Real interview questions, every type

From system design to ML coding to flashcards — drawn from real, reported interviews. Here are a few of the most-viewed.

System Design for ML

Design recsys, serving stacks & data pipelines.

Coding & Leetcode-style

Implement attention, kNN, training loops from scratch.

ML Fundamentals & Algorithms

Bias-variance, gradients, classical ML.

Deep Learning & Architectures

Transformers, CNNs, normalization, optimization.

LLMs & Prompt Engineering

RAG, fine-tuning, evals & inference.

Flashcards & quick recall

Lock in fundamentals across every topic.

Everything in one place

Everything you need to prep — in one place

Scroll through what you get: real company questions, an in-browser coding pad, flashcards, daily paper digests, an ML job board, and progress tracking.

OImplement multi-head attentionHard
ACode a transformer blockHard
MDesign a feature storeMed

Curated company questions

Hundreds of expert-reviewed ML questions, filterable by lab — Google, Meta, OpenAI, Anthropic and more.

Explore
def attention(Q, K, V):
scores = Q @ K.T / sqrt(d)
w = softmax(scores)
return w @ V
▶ pytest
✓ 3 passed in 0.21s

In-browser coding

Write and run ML code in the browser with LeanCode and the coding-practice editor — tests run instantly.

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Flashcard

What problem does RoPE solve in transformers?

Reveal answer →

Flashcards

Quick recall decks across core ML, deep learning, and system design to lock in the fundamentals.

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For you · arXivtoday

Mixture-of-Experts routing at scale

Long-context KV-cache compression

Popular

Personalized Paper Digest

AI-driven digests of new arXiv papers, tailored to your research interests — delivered daily.

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O

ML Engineer, Inference

OpenAI · Remote

Apply
A

Research Engineer

Anthropic · Remote

Apply
D

Applied Scientist

Databricks · Remote

Apply

ML Job Search

Curated ML / AI roles from top labs and startups, matched to your profile and target companies.

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This week
12-day streak · 48 solved

Track your progress

Attempt history, best scores, streaks, and per-company performance so you always know what to study next.

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By Company

Questions by lab

Real reported interview questions, scoped to each lab. Pick a company to see its track.

$ ls ./openai/questionsverified · Coding · Classical · DL/LLM
  • 01Battle MonstersCodingMed
  • 02Classifier AnalysisClassicalHard
  • 03Noisy Human Data Classifier AnalysisClassicalMed
More OpenAI questions
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The honest pitch

Why not just LeetCode?

Generic algorithm grinding doesn't reflect how ML teams actually interview. Here's the difference.

Generic LeetCode
  • Inverting binary trees you'll never touch in an ML role
  • Zero coverage of attention, RAG, training or serving
  • No signal on what a specific lab's loop looks like
  • Generic system design — never ML-specific
Crack ML Interview✓ Verified
  • Real ML questions: implement attention, design a recsys
  • Coding, system design, DL/LLM and classical ML in one place
  • Organized by company so you prep the right loop
  • Every question maps to a real, reported interview