I recently asked a startup CEO for his take on the best AI coding tools . He mentioned the usual suspects: OpenAI's Codex and Anthropic's Claude Code . Then he brought up a less familiar name. "There's another coding agent, Code Puppy, built by an amazing guy called Mike Pfaffenberger at Walmart , " this CEO told me. "It's got masses of usage in Walmart." The tip sent me down a rabbit hole that revealed something much bigger than another AI coding assistant. Code Puppy is part of Walmart's