This review discusses the potential of bottom-up and hybrid bottom-up/top-down strategies for nanoelectronics, with a focus on memory devices based on the crossbar architecture. Bottom-up approaches allow for precise control of material composition and structure at the molecular level, enabling the creation of devices and fabrication methods not achievable with traditional top-down techniques. The review highlights the advantages of crossbar memory structures, which use arrays of crossed nanowires to form memory bits. These structures can be configured as resistive switching elements or configurable field-effect transistors, offering high density and performance. The review also discusses the integration of these memory devices with circuitry, including hybrid crossbar/CMOS circuits and array-based systems. It addresses challenges in scaling and the potential for three-dimensional integration. The review emphasizes the importance of bottom-up fabrication methods in overcoming the limitations of conventional semiconductor scaling and suggests that such approaches could lead to new memory technologies with high density and performance. The review also discusses the potential of hybrid approaches combining bottom-up and top-down techniques for future nanoelectronics applications.This review discusses the potential of bottom-up and hybrid bottom-up/top-down strategies for nanoelectronics, with a focus on memory devices based on the crossbar architecture. Bottom-up approaches allow for precise control of material composition and structure at the molecular level, enabling the creation of devices and fabrication methods not achievable with traditional top-down techniques. The review highlights the advantages of crossbar memory structures, which use arrays of crossed nanowires to form memory bits. These structures can be configured as resistive switching elements or configurable field-effect transistors, offering high density and performance. The review also discusses the integration of these memory devices with circuitry, including hybrid crossbar/CMOS circuits and array-based systems. It addresses challenges in scaling and the potential for three-dimensional integration. The review emphasizes the importance of bottom-up fabrication methods in overcoming the limitations of conventional semiconductor scaling and suggests that such approaches could lead to new memory technologies with high density and performance. The review also discusses the potential of hybrid approaches combining bottom-up and top-down techniques for future nanoelectronics applications.