Interactive system design tool for developers to simulate traffic and explore diagrams
HowItScales is a new platform for interactive system design aimed at developers. The tool lets users follow a request hop by hop as it travels through a system and back. Users can simulate heavy traffic by raising requests per second to watch queues fill, autoscaling kick in, and requests get rejected. The platform supports importing diagrams from draw.io, turning static shapes into living components. Every component carries a label indicating whether information is documented, an assumption, or hypothetical. The tool is designed for developers who work with systems, whether they are new to system design or explaining an existing architecture. It serves purposes including interview preparation, explaining architecture, learning how large systems work, and teaching or mentoring. The platform emphasizes that what users see reflects what is known, with labels distinguishing documented facts from assumptions and hypothetical teaching models. Files remain in the browser and no sign-up is required to use the tool.
About HowItScales: Interactive system design for developers. More at howitscales.dev.
