This document outlines the Lean Startup methodology used at AXA Digital Agency for mobile development. It discusses starting with listening to customers to understand their pain points, developing minimum viable products through an agile process, and continuously learning from customer feedback to iteratively improve products. The goal is to discover product-market fit through measuring customer satisfaction, retention, referrals, and growth. In conclusion, it emphasizes focusing on customers and problems first, taking incremental steps with constant iteration, and leveraging technology throughout the process.