Adapts to any architecture
Sketch a URL shortener, a payments ledger, or a multi-region streaming pipeline — the assistant understands the domain and suggests the right components, not generic boxes.
AI-enabled · adapts to any design
Design systems like a guru.
A fast, collaborative canvas for system-design interviews and architecture sketches — with an AI partner that understands your design, reasons about trade-offs, and reviews it like a staff engineer. Real-time, multiplayer, and calm by design.
- 30sfrom blank canvas to first diagram
- 10+interview perspectives, scored live
- ∞free local diagrams, forever
AI-enabled
An AI partner that adapts to any design.
Most diagram tools just draw what you tell them. sysdesign.guru understands what you’re building. Describe a system in plain language and it appears on the canvas — then it reasons about scale, reliability, and the trade-offs you haven’t thought of yet.
Reasons about trade-offs
Ask “what breaks at 100k QPS?” and get a grounded answer: hot partitions, cache stampedes, the queue that needs a dead-letter. It argues both sides like a staff engineer would.
Designs alongside you
Describe a system in plain language and watch nodes, edges, and data stores appear on the canvas — then refine by dragging, or by asking for a change.
Reviews like an interviewer
Point it at your diagram and it probes the gaps a real panel would: single points of failure, consistency models, back-of-the-envelope math that doesn’t add up.
Interview practice
Walk into the loop already warmed up.
System-design rounds reward people who’ve done the reps. Practice on real prompts, switch perspectives the way an interviewer probes, and get scored before the panel does.
- Practice against real prompts — “design a rate limiter,” “design Twitter’s timeline” — on a timer.
- Switch perspectives in one click: QPS, latency, fan-out, storage, availability.
- Get an honest scorecard on scalability, reliability, and clarity before the real panel does.
- Replay your session to see how your design evolved under pressure.
Design review · Twitter timeline
Scalability92
Reliability78
Data model85
Clarity88
Watch the fan-out on the timeline service — at 100k QPS your cache will stampede.
ERD & data modeling
Model your data in minutes, not afternoons.
Entity-relationship diagrams shouldn’t feel like fighting your tool. Type your tables, and the canvas handles layout, keys, and routing — so the diagram stays readable as the schema grows.
Tables in seconds
Type a few fields and the canvas lays out entities, keys, and types — no dragging boxes pixel by pixel.
Relationships that route themselves
Foreign keys snap into clean, readable edges. Cardinality is obvious at a glance.
Stays legible as it grows
Auto-layout keeps a 40-table schema from turning into spaghetti. Pan, zoom, focus.
Export anywhere
Drop a PNG into a doc, or hand the JSON to your tooling. Your model, your format.
usersid uuid · pkemail textcreated_at timestamptz
ordersid uuid · pkuser_id uuid · fktotal numeric
Loved by engineers
From mock interviews to real design reviews.
“I ran my last three mock interviews on this. The live QPS view caught a fan-out problem I’d have hand-waved past — and then nailed in the real loop.”
“The AI doesn’t just autocomplete boxes. It pushed back on my consistency model the way a good interviewer does. Genuinely changed how I prep.”
“We use it for design reviews now, not just interviews. Sketch the system, ask where it falls over, get a real answer in seconds.”
“ERDs used to take me an afternoon in a clunky tool. Now it’s a coffee break. The auto-routing alone is worth it.”
Free
$0forever
- Unlimited local diagrams
- Full system-design component library
- 10+ interview perspectives (QPS, latency, fan-out…)
- Auto-format, undo/redo & version history
- Export to PNG and JSON
For teams
Pro
$7.99/ seat / month
- Everything in Free
- AI design partner & live diagram review
- Real-time multiplayer rooms
- End-to-end encrypted sessions
- Share links with view / edit roles & expiry
- Live cursors, presence & follow-along
- Comments, reactions & an activity feed
Breathe in. Architect out.
Open a canvas and have your first system designed in under a minute — no signup required.