A senior developer is an experienced software engineer who has advanced skills in programming and software design. They typically have several years of experience and are proficient in multiple programming languages and technologies. Senior developers often take on leadership roles within a team, guiding junior developers and contributing to project planning and architecture. In addition to coding, senior developers are responsible for reviewing code, ensuring quality standards, and mentoring less experienced team members. They often collaborate with other stakeholders, such as project managers and designers, to deliver high-quality software solutions that meet user needs and business goals.