Simulate Real System Design Interviews.

Build Real Depth.

High-fidelity scenarios and open-ended questions. Real time trade-offs. Feel interview ready from the first session.

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Why Serious Candidates Trust PAI To Ace System Design Rounds

Build real judgment under pressure

High-stakes system design interviews test how you think under shifting constraints. PAI mirrors those conditions, sharpening your judgment so you stay clear-headed when top tech companies push you to defend complex decisions in real time.

Defend with confidence when it counts

Get real senior-level pushback, more reps than pricey live mocks, and sharpen how you defend trade-offs — all on your schedule. So you can stand your ground when it counts, with the calm authority that panels trust.

Know what you don’t know

Most prep gives you a score and stops. PAI pushes deeper — probing your answers, surfacing blind spots you’d never spot alone, and giving you clear, actionable fixes. So you’re never blindsided by the follow-ups that stump candidates who only practice the basics.

Engineer Success Story

See how PAI users achieve remarkable results with us.

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A Backend Dev’s Edge for FAANG - Mastering System Design

“I’ve already shared it with friends. I tell other engineers to try it for one session, because that’s all it took for me to realize it works.”

Neel

SDE2, Leading CRM Cloud

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What Our Users Love About PAI

“Unlike other system design prep, Peppermint AI pushes back, challenges your assumptions, and redirects you when you're off track. That's real feedback.”

Neel

Full Stack Developer at a major enterprise software company

“It didn’t let me get away with a vague answer. It pushed me to justify every decision. That’s rare even in live mocks.”

Rishabh

System Design Interviewee

“It’s not just practice, it actually taught me something. Most platforms just scratch the surface, but PAI went deeper and made me realize what I didn’t know.”

Sanskar

Preparing for SDE2 Interviews

“I thought my design was solid, but the AI found all the things I'd completely missed. It really called out my blind spots.”

Keith

Senior Software Engineer

“Using Peppermint AI is so much simpler than booking mock interviews or relying on friends. I could just log in after work and get real practice immediately.”

A Working Professional Interviewing at Night

PAI System Design Solutions

Explore more solutions

Distributed Scheduler

Deconstruct a distributed job scheduler—from architecture to code. We unpack trade-offs: pessimistic DB locking for concurrency control, idempotent APIs to prevent duplicate work, and retries with exponential backoff + jitter.

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FAQ

Mid-to-senior engineers (SDE2+) prepping for high-stakes interviews at top tech companies. If you want your system design depth tested under real pressure — this is for you.

Each session mirrors the stakes, ambiguity, and time constraints of senior-level system design rounds — open-ended, evolving, no canned answers.

Most engineers spend about 60 minutes on a session — just like a real system design round. But there’s no fixed clock: go as deep as you want, pause anytime, and pick up right where you left off.

No scheduling, no waitlists. Log in anytime, pick a scenario, and run your interview on your terms.

Always. Your sessions and feedback stay in your dashboard so you can resume them anytime and review how your depth improves.

Solutions and code analyzer are always free. Just buy credits whenever you’re ready to practice interviews — there’s no subscription, no auto-renew.

A live mock interview with a senior engineer can cost anywhere between $300–$600 an hour — and the quality isn’t always guaranteed! PAI gives you repeatable, high-fidelity sessions for a fraction of that so you build depth, without any bias, on demand, as many times as you want.

Practicing coding rounds too?

Push past the basics.

Use our free coding evaluator to check your solutions — then see how Peppermint AI tests the thinking and judgment that turn good code into systems that scale at the world’s top tech companies.

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