Most system design prep is passive: reading writeups, watching videos, or drawing boxes on a whiteboard that nobody ever load-tests. Code Paradox exists because we wanted the opposite, a place where you build the system for real. Place components, wire up the request path, and submit your design against an actual capacity simulator that checks throughput, latency, reliability, and cost, the same way a real design review would.

The goal isn't to memorize a set of "correct" architectures. It's to build the instinct for tradeoffs, when to add a cache, when to shard, when consistency actually matters, that you'll use in an interview or on the job.

The idea came out of a simple frustration: every other prep resource stops at the diagram. We kept asking, "okay, but does it actually work at scale?", so we built the tool that answers that question.