In coherent optical modules, the Digital Signal Processor (DSP) acts as the brain of the system, processing both incoming and outgoing signals to correct distortions, ensure data integrity, and overcome transmission impairments. The Marvell coherent DSP portfolio, including Orion™, Canopus™ and Deneb™ platforms, empower the optical module ecosystem with low-power, high-performance silicon for QSFP-DD, OSFP and CFP2-DCO coherent pluggable form factors for AI cloud data center interconnect and 5G telecom and long-haul. DSP (Digital Signal Processing) refers to the use of digital computation to manipulate signals such as audio, video, or sensor data. It involves transforming real-world analog signals into digital form, processing them using mathematical algorithms, and converting the processed signals back to. Electronic Digital Signal Processing (DSP) is a key technology for optical transport networks, in particular for coherent optical transmission systems. In optical transponders, it enables carrier recovery and synchronization as well as compensation of linear and non-linear signal interference. They deliver reliable, ultra‑low‑latency performance and strong network resiliency, while Credo's low‑power SerDes architecture provides industry‑leading. While direct detect transmission only uses the amplitude of the light signal, coherent optical transmission manipulates three different light properties: amplitude, phase, and polarization. These additional degrees of modulation allow for faster optical signals without compromising the transmission. This article provides a comprehensive overview of the different functions within the electronic engine of the coherent transceiver, with a focus on the DSP, and summarizes the latest developments and future challenges of DSP technology. In recent decades, global Internet traffic has grown.