<p>This study presents a reverse engineering approach to improve product circularity, considering CO₂ emissions and costs across the full product life cycle, demonstrated using a robot gripper frame. The proposed approach closes a research gap by providing a practical, systematic method that links quantitative results with reverse engineering thinking to identify product-specific circularity bottlenecks and derive concrete design improvements without causing environmental or economic trade-offs. Starting from a state-of-the-art aluminum structure, the study develops a novel lightweight design that utilizes carbon fiber–reinforced tubes and 3D-printed polyamide-based nodes. Life Cycle Assessment, Life Cycle Costing, and Life Cycle Gap Analysis are used to assess the environmental, economic, and circularity performance of the concepts. While the lightweight composite structure significantly reduces energy demand in the manufacturing (− 51.18%) and use phases (− 19.46%), it simultaneously worsens circularity performance, reflected by a 30.17% increase in the Life Cycle Gap. By applying the reverse engineering approach to the lightweight composite structure, non-reversible material and process choices are identified and replaced, specifically by using thermoplastic materials instead of thermosets to enable recyclability. The optimized composite structure leads to a 19.44% reduction in the life cycle gap, with simultaneous further reductions in carbon footprint of 0.23% and costs by 0.2%.</p>