A new free, AI-generated quiz every day — 5 multiple-choice questions spanning all 27 system design patterns. Answer, learn from the per-question explanations, and build a daily streak. Daily and all-time leaderboards, with one scored attempt per day and unlimited practice rounds. No sign-in needed to play; sign in to save your score.
A free, beginner-friendly system design workbook — Fundamentals, Core Building Blocks, and 27 Design Patterns explained in depth with examples and trade-offs. Collapsible left-glued sidebar that highlights your current lesson, a circular reading-progress ring, and cross-device progress tracking with green ticks for completed lessons.
A refreshed, quick-reference cheatsheet of all 27 design patterns — friendlier and far less cluttered, organized by category with collapsible sections so you can scan and recall fast before an interview.
A search bar on the Learn hub matches anything you type to the right lesson or pattern, so you can jump straight to the topic you need.
The /learn page now leads with clear entry points — jump straight into the Workbook, Cheatsheet, or Daily Drills — plus progress bars showing how far you've read.
Canonical URLs, Open Graph and per-lesson OG images, and JSON-LD structured data across the public Learn, Cheatsheet, and Drills pages for better discoverability.
New free-text field alongside the canvas — explain your component choices, data flow, and key tradeoffs as if talking to an interviewer. AI reads both the diagram and your explanation together. Concrete reasoning earns real credit; vague claims don't.
Critical issues no longer force a diagram redraw. Respond with how you'd fix it in text — AI evaluates your response and updates the verdict. Severity label is preserved so you always know what mattered most.
Entities and capacity reviewers are now lenient-on-format, strict-on-reasoning. Your explanation is shared with all reviewers as first-class evidence. Fewer noisy criticals — only real issues get flagged.
The Drawing Guide and AI Setup Guide are now publicly accessible — no sign-in required. Includes a new 'Explain Your Design' section showing how to use the explanation panel effectively.
The homepage animated demo now includes the explanation panel stage, showing new users how to walk through their design before submitting.
New system design challenge every Monday. One-shot submission with AI review, leaderboard ranked by hire signal, streak tracking, and pre-filled requirements. Free for everyone — doesn’t use your monthly quota.
Three-tab layout: Official Topics (51 curated problems with difficulty badges), Community Topics, and My Designs. Each topic page now shows requirements, scale expectations, collapsible hints, estimated time, and related topics.
All 51 official topics now include difficulty level (Easy/Medium/Hard), problem brief, key requirements, scale expectations, hints, estimated time, and related topic links.
Defend your design choices inline — explain why you picked a certain database, queue, or caching strategy. The AI evaluates your response and gives a verdict.
After responding, request a re-evaluation. The Lead Reviewer reconsiders your hire signal based on your responses — just like a real interview debrief.
Connect your own Gemini (free) or Azure OpenAI key for unlimited reviews. Three options: DrawLint AI (managed), Gemini AI (free), Azure OpenAI (advanced).
Unified provider abstraction layer with retry logic, JSON extraction, and concurrency control. Supports Azure OpenAI Chat Completions, Azure AI Foundry Responses API, and Gemini REST API.
Validate your API key before saving. Connection must pass before config is saved.
Animated AI Review Pipeline with respond step, count-up stats, particle background CTA, and enhanced feature cards with hover effects.
6 animated SVG canvas previews showing template layout, components, data flows, annotations, clusters, and writeup sections.
Filter designs by level, signal, provider, and sort by date or topic.
Toggle all feedback sections at once in the review panel. Count badges show highlights, warnings, and resolved issues per section.
Intelligent diagram analysis — extracts components, connections, annotations, and clusters from Excalidraw elements. Connection-based annotation linking.
Pro subscribers get a 👑 badge on their submissions in the library and header.
Added ‘AI-generated · Use your own judgment’ notice with warning icon on all review results.
Privacy Policy, Terms of Service, cookie consent banner, email compliance, signup consent text, and legal footer links.
robots.txt, sitemap, PWA manifest, JSON-LD structured data, and page-specific titles and descriptions.
About page with mission, tech stack, and contact info. Changelog page with full feature timeline.
Excalidraw-based canvas, 6 AI reviewers (NFR, Entities, Capacity, API, HLD + Lead Reviewer), peer library, draft save, share links, and authentication (email, Google, GitHub).