In a modular supply chain, coordination between module producers is often ensured by a leading firm, which plays the role of architect role. This article questions the relevance of a pure architect strategy where a non-producer is in charge of coordinating modules. A firm’s success relies on attaining two objectives: technological efficiency and competitive position. The Airbus case shows that a pure architect strategy can ensure technological efficiency, but the architect’s competitive position is weakened by this strategy. Firms in architect positions must develop complementary strategies, namely the production of a critical module like Airbus, and keep in-house certain strategic competences in-house. By introducing strategic issues, this article aims to overcome the purely technological view of firm’s efficiency in a modular supply chain. JEL L22, L23, L93, D23, O33.