Chip-scale optical frequency combs have emerged as novel light sources that may disrupt many applications in science and industry. On a technical level, microcombs offer a multitude of narrow-linewidth phase-locked optical carriers that are spaced by free spectral ranges of tens or even hundreds of GHz. This feature makes the devices particularly well-suited for massively parallel optical communications and ultra-broadband photonic-electronic signal processing. In this talk, we will present an overview of our recent progress related to chip-scale optical frequency combs. We will cover numerical models, hybrid integration technologies, as well as application demonstrations of microcombs in the fields of optical arbitrary waveform generation and measurement (OAWG/OAWM), high-symbol-rate optical communications, as well as photonic-electronic analogue-to-digital conversion.