The discovery of gravitational waves and their complementary signatures has transformed astrophysics, unlocking new opportunities to explore and understand the universe. Advancements in gravitational-wave detector technology, alongside progress in electromagnetic and neutrino observatories, have enabled a synergistic approach to cosmic discovery. On the observational front, this talk will explore key breakthroughs, lessons, and ideas relevant for gravitational-wave astrophysics, emphasizing the integration of data across these observatories to achieve deeper understanding. Despite remarkable progress, the frequency band around 0.1-1 Hz remains unexplored by gravitational-wave detectors, holding immense potential for studying phenomena such as intermediate-mass binary black hole mergers, early inspirals of compact binaries, and comprehensive multiwavelength observations with instruments like the fantastic Einstein Telescope. I will introduce the idea of the Artificial Precision Timing Array (APTA), an innovative space-based gravitational-wave detector concept based on pulsar timing principles. By using satellites equipped with precision clocks to emit signals toward a central receiver, APTA aims to access the untapped frequency range. This talk will highlight some of the clock attributes required for APTA to pioneer a new era in gravitational-wave research as clock technologies advance in the coming decade.