Synthetic biology aims to engineer novel genetic circuits with predictable behavior for diverse applications in biotechnology, medicine, and research. However, inherent resource competition within biological systems poses significant challenges to achieve this predictability. This review highlights the importance to account resource competition in the design and analysis of synthetic genetic circuits. These studies revealed how competition for regulatory proteins, proteases, ribosomes, ATP, DNA-binding sites, and other cellular resources affects the functionality and stability of these circuits. Therefore, this discussion underscores the need to enhance the robustness and stability of molecular systems by harnessing their inherent features. It also offers valuable insights into unexplored design principles that have yet to be applied in the field of molecular robotics.