A Lambda Architecture developer designs and implements large-scale data processing systems using the Lambda Architecture framework. This involves managing real-time and batch data processing. They create fault-tolerant systems that can handle massive data quantities, ensuring data accuracy and low latency. They integrate data from disparate sources, process it, and make it available for analysis and machine learning. They develop and maintain scalable and distributed systems, and work with tools like Apache Kafka, Hadoop, Spark, and NoSQL databases. They also continuously monitor system performance, troubleshoot issues, and implement improvements to meet evolving data needs.