Human spinal curvature varies across individuals and postures, creating different support needs along the back and pelvis. Responding to this fact, this project develops a fabrication-driven chair that can adapt its support profile from shoulder to hip. By quantifying spine alignment with ergonomic curvature metrics and translating them into a parametric workflow—curve segmentation, radius-driven mechanical simulation, contour extraction, and profile lofting—the system generates a continuous body-matched surface rather than a fixed, generic backrest. The resulting geometry is then discretized into repeatable components and assembled through a wood-and-weave construction logic, enabling rapid prototyping and material testing. Through iterative fabrication and full-body trials in multiple lounging positions, the project demonstrates how ergonomic data can directly inform a buildable chair system, bridging measurable posture differences and hands-on making.