LowLevelDesign Mastery: Visual-first LLD practice with diagrams, code & AI reviews

Hey Product Hunt 👋 I built LowLevelDesign Mastery while preparing for backend interviews myself. What I struggled with most wasn’t understanding concepts — it was practicing LLD the way interviews actually happen: asking clarifying questions, identifying entities, designing class diagrams, applying patterns, and then writing clean code. Most resources stop at theory or PDFs. I wanted a place where you can: Learn concepts visually Practice real LLD problems step-by-step Get structured feedback and compare approaches The playground, visual cheat sheets, and AI review came directly from pain points I faced during prep. I’d love honest feedback — especially from folks who’ve interviewed or are preparing right now. Happy to answer any questions!