A Kafka developer designs, builds, and maintains real-time data pipelines and streaming applications using Apache Kafka, an open-source stream-processing software platform. They manage data flow, ensure optimal data quality, and handle data integration. Their tasks include deploying, monitoring, and troubleshooting Kafka clusters, improving data processing methods, and collaborating with other teams to implement data strategies. They also ensure system security and data privacy. The developer needs to be proficient in programming languages like Java, Python, or Scala, and have a strong understanding of distributed systems and big data ecosystems.