Every day, we read of a new case where a product’s data processing, algorithms, machine learning and automated decision-making are creating problematic political, environmental, social and legal impacts. The new technologies embedded inside of new products have unpredictable and deeply complex impacts and the context of product use is shifting constantly. We designed The Ethical Stack to support creators of new technology to consider ethics in their product development. It is an interactive website and service that guides creators of new technology through a series of exercises to practice ethics. The website challenges preconceived notions of what it means to be ethical through ethical dilemmas and unusual angles.