A codecs developer designs, implements, and optimizes algorithms for compressing and decompressing data, particularly audio and video files. They work on encoding and decoding digital data streams or signal transmissions over various platforms. Their responsibilities include improving existing codecs, developing new ones to enhance data transmission efficiency, and troubleshooting any issues that arise. They also need to ensure the compatibility of codecs across different devices and platforms. Their work involves a deep understanding of digital signal processing, computer programming, and data compression techniques. They often work closely with software engineers and multimedia developers.