This review discusses the potential of bottom-up approaches in nanoelectronics, particularly focusing on crossbar-based memory devices. Bottom-up methods, which involve molecular-level control of material composition and structure, offer advantages over top-down techniques in terms of device density and performance. The review highlights the development of electromechanical and resistance-change memory devices based on carbon nanotubes and core-shell nanowires, respectively, which exhibit robust switching and promising performance metrics. It also explores architectures for circuit-level integration, including hybrid crossbar/CMOS circuits and array-based systems, with experimental demonstrations of key concepts such as lithography-independent, chemically coded stochastic demultiplexers. Additionally, the review discusses bottom-up fabrication approaches, including the assembly of three-dimensional, vertically integrated multifunctional circuits. The authors emphasize the importance of addressing challenges in commercializing these technologies, such as improving device yield, endurance, and retention time, and the need for collaboration between chemists, physicists, and engineers to realize the full potential of bottom-up nanoelectronics.This review discusses the potential of bottom-up approaches in nanoelectronics, particularly focusing on crossbar-based memory devices. Bottom-up methods, which involve molecular-level control of material composition and structure, offer advantages over top-down techniques in terms of device density and performance. The review highlights the development of electromechanical and resistance-change memory devices based on carbon nanotubes and core-shell nanowires, respectively, which exhibit robust switching and promising performance metrics. It also explores architectures for circuit-level integration, including hybrid crossbar/CMOS circuits and array-based systems, with experimental demonstrations of key concepts such as lithography-independent, chemically coded stochastic demultiplexers. Additionally, the review discusses bottom-up fabrication approaches, including the assembly of three-dimensional, vertically integrated multifunctional circuits. The authors emphasize the importance of addressing challenges in commercializing these technologies, such as improving device yield, endurance, and retention time, and the need for collaboration between chemists, physicists, and engineers to realize the full potential of bottom-up nanoelectronics.