The metrology and transduction of terahertz waves is a prerequisite for future applications in communications, sensing, monitoring or high speed control of light. With past technologies mainly limited to radio frequencies, terahertz waves are anticipated to boost current functionalities. On one hand side, they can be carriers of unique information e.g. chemical information about gases, plastics or water content for spectroscopy or environmental monitoring. On the other hand side, they can be utilized to control optical signals at ever faster speeds – in so-called transducers that link the terahertz with e.g. the optical domain on sub-picosecond timescales. A large variety of applications require terahertz compatibility but reaching the terahertz is still an outstanding challenge. The reason is that, to date, the vast majority of terahertz technologies rely on bulky and inefficient optics. This severely limits their functionality. In this talk, I discuss promising integrated photonic technologies from state-of-the art electro-optic materials that provide unique possibilities to engineer terahertz systems at the nanoscale with applications in metrology and high-speed control of light.