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Used by Palantir & FAANG candidates

Practice the interview rounds LeetCode skips.

Carry a case from clarify to build, with an AI interviewer that reacts as you work. Built for intern and new-grad SWE and DE loops.

The gap

You drilled puzzles.
They tested the job.

You solved hundreds of LeetCode problems. Then the interview opened a real codebase and asked you to find the bug, or handed you an ambiguous system to scope.

What you practiced

  • Reverse a binary tree
  • Two Sum
  • Sliding-window maximum

What they actually ask

  • Fix a failing test in a real codebase
  • Scope a vague, real-world system
  • Ship a feature without breaking the build

Closing that gap is the entire product.

See a real Case Lab
Company-tailored prep

Tell us where you're interviewing. We build the plan.

Pick your target company and role. We map the rounds they actually run, then turn them into a week-by-week plan. It draws on the same real-question library behind our Case Labs.

Where are you interviewing?
Palantir· FDSE
PalantirStripeMetasoonAmazonsoon
Your 4-week plantailored
  1. Week 1Scope ambiguous problems
  2. Week 2Design under real constraints
  3. Week 3Fix failing tests in a real repo
  4. Week 4Run the full timed loop

How our AI grades you

Real Interview Scoring

What you're evaluated on

Understanding
25%
Problem-Solving
25%
Code Quality
20%
Communication
30%

The goal: Can you solve problems, explain your thinking, and write clean code?

The practice system

Every format. One feedback loop.

From raw algorithm optimization to full FAANG loops. Click any node to explore the journey, then drill into each format below.

Learn Patterns
Code Live
Get Feedback
Track Gaps
Mock Rounds
Ship the Offer

DSA Patterns

Master 15+ core algorithmic patterns. From Sliding Windows to Advanced Graphs, learn to recognize patterns rather than memorizing problems.

  • Pattern recognition practice
  • Time & space complexity analysis
  • Progressive optimal approach hints

The pattern-retention problem

You forget 80% within a week

MemoryDay 1Day 3Day 7Day 3020%90%
Random practice
With CodeSparring

The DSA patterns you drill fade fast. We resurface each one at the right moment, just before you'd forget it.

Learn the science
Performance analytics

See exactly where you stand.

Every session becomes one readiness score, your weakest patterns, and the next move for your practice.

78%Ready

Interview readiness

One score, calibrated to real FAANG rubrics, updated after every session.

Pattern mastery

Arrays92%
Trees75%
Graphs58%

Bar = you · tick = FAANG average

Progress

+12%this month

Week-over-week, so real gains stand out from a one-session spike.

Adapts to you

Detects whether you stall on setup, edge cases, or explaining, then targets it.

What gets trackedTest pass rateHint usageCommunicationProblem solvingTime to solvePattern coverage

What interview prep costs

5+ mock interviews significantly improve pass rates. Here's what that investment looks like.

Human Mock Interviews

Interviewing.io, Pramp Pro, etc.

$0$0

$150–225 per session × 5 sessions

Real human feedback
Requires scheduling in advance
CodeSparring

AI mock interviews on demand

$0/month

Cancel anytime

AI adapts to your skill level
Practice at 2am before your 9am interview

One month costs less than a single human mock session.

Feature
LeetCode$35/mo
Human$150+
Ours$25/mo
Practice speaking through solutions
Available 24/7, no scheduling
Real-time hints while coding
Consistent feedback quality
N/A
Varies
Spaced repetition system
Practice anytime, 24/7

No credit card required