System Design Sandbox is the interactive playground for system design interviews. Drag and drop real components (load balancers, caches, Kafka, shards, etc.), build your architecture, and get instant AI feedback that catches missing rate limiters, single points of failure, wrong consistency choices, and more with clear fixes. TinyURL scenario is live and 100% free, no signup. More scenarios drop every week. Stop drawing boxes on Excalidraw. Start practicing the way you think.

BoreSync is a mindfulness app. You sit with boredom on purpose. Solo or with friends. No music. No guides. Just a timer. Join a group with a code. See who is with you live. Switch apps? Get a 10-second penalty ("You blinked!"). After, see your score (time minus penalties). Write one note. Share it. Track stats and badges. Works offline. Add to iPhone home screen. Built fast with AI. Inspired by digital detox. Try it: boresync.com. Who lasts longest?