This paper presents a breakthrough in optical communications using dissipative Kerr solitons (DKS) generated in silicon nitride microresonators for massively parallel coherent optical communications. DKS are generated through four-photon interactions in an integrated silicon nitride microresonator, resulting in low-noise, spectrally smooth, and broadband optical frequency combs. These combs are used as both multi-wavelength light sources at the transmitter and as local oscillators (LO) at the receiver for coherent detection. The study demonstrates the transmission of data streams at rates exceeding 50 Tbit/s using 179 optical carriers spanning the entire telecommunication C and L bands. The results show that DKS combs can replace arrays of continuous-wave lasers in high-speed communications, offering significant scalability advantages. The approach also enables efficient compensation of impairments caused by nonlinearities in the transmission fiber. The study highlights the potential of DKS combs for chip-scale petabit/s transceivers, combining with advanced spatial multiplexing schemes and highly integrated silicon photonic circuits. The experiments demonstrate the stability and performance of DKS combs, showing that they can achieve high data rates with low bit-error ratios (BER) and high spectral efficiency. The results prove the tremendous potential of DKS comb generators for high-speed data transmission, both in petabit/s intra-datacenter networks and in inter-datacenter connections. The study also shows that DKS combs can be used as multi-wavelength LOs at the receiver, achieving high data rates with low BER and high spectral efficiency. The results demonstrate the potential of DKS combs for future high-speed optical communications, offering a scalable and efficient solution for massive parallel data transmission.This paper presents a breakthrough in optical communications using dissipative Kerr solitons (DKS) generated in silicon nitride microresonators for massively parallel coherent optical communications. DKS are generated through four-photon interactions in an integrated silicon nitride microresonator, resulting in low-noise, spectrally smooth, and broadband optical frequency combs. These combs are used as both multi-wavelength light sources at the transmitter and as local oscillators (LO) at the receiver for coherent detection. The study demonstrates the transmission of data streams at rates exceeding 50 Tbit/s using 179 optical carriers spanning the entire telecommunication C and L bands. The results show that DKS combs can replace arrays of continuous-wave lasers in high-speed communications, offering significant scalability advantages. The approach also enables efficient compensation of impairments caused by nonlinearities in the transmission fiber. The study highlights the potential of DKS combs for chip-scale petabit/s transceivers, combining with advanced spatial multiplexing schemes and highly integrated silicon photonic circuits. The experiments demonstrate the stability and performance of DKS combs, showing that they can achieve high data rates with low bit-error ratios (BER) and high spectral efficiency. The results prove the tremendous potential of DKS comb generators for high-speed data transmission, both in petabit/s intra-datacenter networks and in inter-datacenter connections. The study also shows that DKS combs can be used as multi-wavelength LOs at the receiver, achieving high data rates with low BER and high spectral efficiency. The results demonstrate the potential of DKS combs for future high-speed optical communications, offering a scalable and efficient solution for massive parallel data transmission.