Certain aspects relate to imaging systems and methods for manufacturing imaging systems and image sensors. The imaging system includes a pixel array including a plurality of pixels, the pixels configured to generate a charge when exposed to light and disposed on a first layer. The imaging system further includes a plurality of pixel circuits for reading light integrated in the pixels coupled thereto, each of the plurality of pixel circuits comprising one or more transistors shared between a subset of the plurality of the pixels, the one or more transistors disposed on a second layer different than the first layer. The imaging system further includes a plurality of floating diffusion nodes configured to couple each of the plurality of pixels to the plurality of pixel circuits.