LeetCode for system design — Now in Early Access

The system design
interview platform.

Engineers practice here to land roles at Google, Meta, and Amazon. Companies screen here because the signal is real.

Real voice conversation. Live whiteboard. Adaptive AI that probes like your toughest interviewer. Honest feedback in seconds.

Free forever · No credit card · 3 sessions/month on the free plan

100+
System design problems
Across 12 domains
5
Seniority levels
L3 through Principal
<30s
To first AI question
No setup required
95%
Cheaper than a phone screen
Fraction of $300 senior eng time

See It In Action

Watch a live interview session

See how DesignLoop conducts a real system design interview — voice conversation, live whiteboard, and honest AI feedback in seconds.

DesignLoop · System Design Interview
Live
00:04:32
AI
Interviewer · Adaptive Mode

"Design a URL shortening service like bit.ly. Walk me through your architecture, starting with the core write path."

Candidate

"I'd start with a simple REST API — POST /shorten returns a short code, GET /:code redirects. We need a key generation service to avoid collisions..."

Architecture72
Communication85
Scalability58
Whiteboard
ClientLoadBalancerAPIServiceKey GenServiceRedisCachePostgres+ ReplicamissCDN(future)↳ 100B URLs · p99 redirect <10ms · 10K writes/s
Watch Demo
Real AI interviewer
Live whiteboard
Instant feedback

The Vision

Engineers practice here.
Companies hire from here.

The engineers who use DesignLoop to prepare are the same engineers your team wants to interview. We're building the infrastructure layer for technical hiring at scale.

01Engineers Practice

Engineers use DesignLoop to prepare — real problems, real AI interviews, honest scoring. They get better, they get hired.

02Companies Screen

Engineering teams invite candidates through DesignLoop. Same platform, same rubric — just the other side of the interview.

03Network Effect

Candidates who trained on DesignLoop arrive better prepared. Screeners get a stronger signal. Both sides win.

What People Say

From both sides of the interview

"

I went from consistently failing L5 panels to landing an offer at Google in 6 weeks. The feedback after each session was brutally honest in the best way.

Software Engineer, L5

Used DesignLoop to prep

"

I reviewed three candidates before my morning standup. None of them needed to schedule with an engineer.

Engineering Recruiter

Series B · 200+ eng

"

The seniority assessment matched exactly what our panel concluded after a 4-hour on-site. The signal is real.

VP of Engineering

Enterprise SaaS team

Ready to start?

Whether you're an engineer prepping for your next system design loop, or a team that needs to screen candidates at scale — DesignLoop is ready.

For Teams

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20+ interviews/month? Get a personalized walkthrough and enterprise pricing discussion.

enterprise@designloop.ai · Responds within 2 hours

For Engineers

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No credit card required. 3 sessions/month on the free plan. Get honest AI feedback in seconds.

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DesignLoop

The system design interview platform — built for engineers who want to go deeper.

By ThyncLabs · © 2026 · Early Access

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