As algorithmic control (AC)—broadly defined as the managerial use of algorithms to direct, evaluate, and discipline workers—is increasingly implemented across a wide range of organisations, understanding how workers judge the legitimacy of AC becomes ever more critical. While prior research in this area often remains fixated on the effects of individual AC mechanisms, our study adopts a system-level perspective on AC. Specifically, we propose a three-layered conceptual framework for AC systems—consisting of (1) a control layer, (2) a data layer, and (3) an organisational embedding layer—and identify key design choices within each layer. Based on this framework, we conducted an experimental vignette study with 329 workers to assess how these design choices affect workers’ perceptions of autonomy and exploitation and, ultimately, their legitimacy judgments of AC systems. Our study advances research by shifting the focus beyond the level of individual control mechanisms to the system level and by providing empirical evidence that workers’ legitimacy judgments are highly sensitive to managerial design choices along all three layers. In particular, our results suggest that design choices within the data and organisational embedding layers are at least as critical as the AC mechanisms themselves in shaping workers’ judgments.