A Hadoop and NoSQL developer designs, develops, and manages big data solutions. They primarily use Hadoop, a framework for distributed storage and processing of large datasets, and NoSQL databases, which provide a mechanism for data storage and retrieval that is modeled differently than relational databases. They handle data ingestion, processing, and extraction to provide analytics insights. Responsibilities include data modeling, database indexing, and developing ETL tools and processes. They also troubleshoot and resolve data storage and processing issues, ensuring optimal performance. Additionally, they work with data scientists, analysts, and other stakeholders to meet business requirements.