A ceramics-based 100 Gbps optical transceiver engine is demonstrated. A ceramics-based interposer is fabricated using the multilayer thick film (MLTF) and photo-imageable thick film (PITF) technologies, which allow for multilayer metallization and ultra-fine resolution. The packaging method requires several flip-chip bonding steps using industry standard solder reflow and ultrasonic bonding processes. The assembled 4-channel optical engine performs error-free at 25.78 Gbps. Bit error rates (BER) and eye diagrams for all channels for both transmitter and receiver side are measured. Further, a crosstalk below 0.4 dB from adjacent channels is measured.