Abstract: GaAs/AlGaAs heterostructures have served as one of the most ideal material systems for studies of electron interactions in mesoscopic physics for the past three decades. The high quality of the 2D electron gases that can be generated in these structures has enabled a wide range of research in topics such as the search for non-Abelian states of matter in the fractional quantum Hall regime and scaleable spin-based quantum computation. In this talk, I will present my work on advancing the state-of-the-art in GaAs materials and devices. In particular, I will discuss advances our group has made to reach low temperature electron mobilities as high as 32 x 106 cm2/Vs and the impact this has had on work in the quantum Hall regime and with spin qubits. In addition, I will discuss progress with density-tuneable devices intended to search for phase transitions in the fractional quantum Hall state at ν = 5/2. Finally, I will present initial results from our work to improve the charge stability of devices useful for spin-based qubits.