A High Availability (HA) developer is responsible for designing, implementing, and maintaining systems that ensure maximum uptime and reliability of an organization's services. They create redundant, scalable systems that can handle failures without disrupting service. This includes setting up and managing databases, servers, and networks to function continuously even during maintenance or unexpected outages. HA developers monitor system performance, troubleshoot issues, and perform disaster recovery operations. They also write code to automate processes and ensure seamless failovers. Furthermore, they work closely with other IT professionals to develop policies and procedures to maintain system integrity and security.