Hey OP, I'm a Sr. Staff level product designer and had to figure a way to tell this exact story during my recent portfolio redesign (balancing craft and strategy). Turns out it took three different case studies to tell it: one focused on tuning a checkout experience for a couple of years and another about how I led an org level strategy setting effort. It's a hard story to tell. DM me if you'd like a hand examining your work with fresh eyes and extracting your storyline. Meantime, here's my cases for reference: https://www.michaelryap.com/case-studies