Entrepreneurship scholars increasingly turn their attention to Corporate Venture Building (CVB). Despite a burgeoning interest, however, extant literature provides limited guidance on how to design an effective CVB process. To address this issue, we conduct an Echeloned Design Science Research (eDSR) study. Drawing on a Theory-Based View (TBV) on Entrepreneurship, we develop a stage-gated CVB process - the Liminal Process Model - to launch new ventures under Knightian uncertainty. The process consists of a cognition-based Discovery phase, and an action-based Design phase, guiding new business opportunities from an unknown state to the point of a Launch decision by the corporate. This study makes four contributions. It shifts the discourse on CVB from a predominantly descriptive-explanatory approach to a design-oriented one. Second, it contributes to corporate entrepreneurship literature by introducing a theoretical design object in the form of a process model. Third, it makes a design evaluation contribution by identifying process and outcome requirements of relevant stakeholders. Lastly, it provides practitioners with a comprehensive toolkit that enhances the effectiveness and practical applicability of CVB.