At this level, individuals have a basic understanding of Apache NiFi and its purpose. They are aware of the concept of data flow management but may not have hands-on experience with the tool. Their knowledge is theoretical and they might need guidance to apply it practically.

Novices can install and configure Apache NiFi and understand its web-based user interface. They can create simple data flows and have an understanding of NiFi's FlowFile concept and data provenance. However, their skills are limited and they may require assistance for complex tasks.

Intermediate users have a good understanding of NiFi's repositories and can handle errors and system failures. They can use processors and NiFi's Expression Language effectively. They are capable of managing more complex tasks independently but may still need help with advanced features.

Advanced users can create complex data flows and understand NiFi's clustering and security features. They can optimize NiFi performance and integrate it with other systems. They have a good understanding of NiFi's REST API. They can handle most tasks independently and troubleshoot common issues.

Experts have a deep understanding of NiFi's architecture and components. They can troubleshoot complex issues, optimize NiFi for large-scale deployments, and customize and extend NiFi. They have a deep knowledge of NiFi's internals and can secure NiFi in various environments. They can handle all tasks independently and provide guidance to others.