New circuit architectures and technologies for high-speed electronic and photonic integrated circuits are essential to realize optical interconnects with higher symbol rate. As a consequence of the increasing speeds, close integration and co-design of photonic and electronic chips have become a necessity to realize high-performance transceivers with novel packaging approaches. Extensive co-design also enables the design of new electro-optic architectures to create and process optical signals more efficiently. This paper and presentation will illustrate a number of recent developments of application-specific high-speed electro-optic transceiver circuits including e.g. broadband driver amplifiers, transimpedance amplifiers, analog equalizers ...